According to the HTTP/1.1 Spec:


In other words, POST is used to create.


That is, PUT is used to create or update.

So, which one should be used to create a resource? Or one needs to support both?

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    It may be helpful to use the definitions in HTTPbis - Roy put a fair amount of work into clarifying them. See: tools.ietf.org/html/… – Mark Nottingham Oct 23 '11 at 21:03
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    Just to bring @MarkNottingham's comment to the latest revision, here's POST and PUT, as defined on HTTPbis. – Marius Butuc Nov 18 '12 at 1:58
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    It seems to me that this debate has arisen from the common practice of oversimplifying REST by describing the HTTP Methods in terms of CRUD operations. – Stuporman Feb 14 '13 at 17:05
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    Unfortunally the first answers are wrong about POST. Check my answer for a better explanation of the differences: stackoverflow.com/a/18243587/2458234 – 7hi4g0 Nov 25 '13 at 5:21
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    PUT and POST are both unsafe methods. However, PUT is idempotent, while POST is not. - See more at: restcookbook.com/HTTP%20Methods/put-vs-post/… – Dinesh Saini Jan 10 '14 at 20:26

32 Answers 32



Both PUT and POST can be used for creating.

You have to ask "what are you performing the action to?" to distinguish what you should be using. Let's assume you're designing an API for asking questions. If you want to use POST then you would do that to a list of questions. If you want to use PUT then you would do that to a particular question.

Great both can be used, so which one should I use in my RESTful design:

You do not need to support both PUT and POST.

Which is used is left up to you. But just remember to use the right one depending on what object you are referencing in the request.

Some considerations:

  • You can update or create a resource with PUT with the same object URL

An example:

I wrote the following as part of another answer on SO regarding this:


Used to modify and update a resource

POST /questions/<existing_question> HTTP/1.1
Host: www.example.com/

Note that the following is an error:

POST /questions/<new_question> HTTP/1.1
Host: www.example.com/

If the URL is not yet created, you should not be using POST to create it while specifying the name. This should result in a 'resource not found' error because <new_question> does not exist yet. You should PUT the <new_question> resource on the server first.

You could though do something like this to create a resources using POST:

POST /questions HTTP/1.1
Host: www.example.com/

Note that in this case the resource name is not specified, the new objects URL path would be returned to you.



For a new resource:

PUT /questions/<new_question> HTTP/1.1
Host: www.example.com/

To overwrite an existing resource:

PUT /questions/<existing_question> HTTP/1.1
Host: www.example.com/
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    I think one cannot stress enough the fact that PUT is idempotent: if the network is botched and the client is not sure whether his request made it through, it can just send it a second (or 100th) time, and it is guaranteed by the HTTP spec that this has exactly the same effect as sending once. – Jörg W Mittag Mar 10 '09 at 15:17
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    @Jörg W Mittag: Not necessary. The second time could return 409 Conflict or something if the request has been modified in meantime (by some other user or the first request itself, which got through). – Mitar Nov 27 '11 at 23:28
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    If I'm not mistaken, what we should be stressing is that PUT is defined to be idempotent. You still have to write your server in such a way that PUT behaves correctly, yes? Perhaps it's better to say "PUT causes the transport to assume idempotence, which may affect behavior of the transport, e.g. caching." – Ian Ni-Lewis Dec 28 '11 at 2:05
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    @JörgWMittag Idempotence catchphrase? How about "Send and send and send my friend, it makes no difference in the end." – James Beninger Mar 3 '14 at 17:13
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    Thinks of them as: PUT = insert or update; POST = insert. So when you make two PUT - you get the one new record, when you do two POSTs - you get two new records. – Eugen Konkov Aug 22 '16 at 9:34

You can find assertions on the web that say

Neither is quite right.

Better is to choose between PUT and POST based on idempotence of the action.

PUT implies putting a resource - completely replacing whatever is available at the given URL with a different thing. By definition, a PUT is idempotent. Do it as many times as you like, and the result is the same. x=5 is idempotent. You can PUT a resource whether it previously exists, or not (eg, to Create, or to Update)!

POST updates a resource, adds a subsidiary resource, or causes a change. A POST is not idempotent, in the way that x++ is not idempotent.

By this argument, PUT is for creating when you know the URL of the thing you will create. POST can be used to create when you know the URL of the "factory" or manager for the category of things you want to create.


POST /expense-report


PUT  /expense-report/10929
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    I agree, wherever idempotence is concerned it should trump any other concerns since getting that wrong can cause many many unexpected bugs. – Josh Oct 26 '10 at 5:56
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    If POST can update a resource, how is that not idempotent? If I change a students age using PUT and do that 10x times the students age is the same if I did it once. – Schneider May 6 '11 at 10:54
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    @Schneider, in this case your server is making an extra effort to guarantee idempotence, but it is not advertising it. Browsers will still warn the user if they try to reload such a POST request. – Tobu Jan 6 '12 at 10:53
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    @Schneider POST may create a subsidiary resource; hence you can POST to collection, like POST /expense-reports and it would create as many entities (expense reports) on your server as the quantity of requests you've sent, even if they are completely similar. Think of it as inserting the same row in the DB table (/expense-reports) with auto-incremented primary key. Data remains the same, key (URI in this case) is generated by server and is different for every other insert (request). So, POST effect can be idempotent, but also may not. Hence, POST is not idempotent. – Snifff Jan 26 '12 at 17:32
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    Let's say we have entities which may have two properties - name and date. If we have an entity with an existing name and date, but then make requests to it specifying only a name, the proper behavior of PUT would be to obliterate the date of the entity, whereas POST may update only the properties specified, leaving the unspecified properties as they were before the request was made. Does that sound correct/reasonable, or is it an improper use of PUT (I saw references to PATCH, which it seems would be more appropriate, but doesn't exist yet)? – Jon z May 8 '13 at 18:28
  • POST to a URL creates a child resource at a server defined URL.
  • PUT to a URL creates/replaces the resource in its entirety at the client defined URL.
  • PATCH to a URL updates part of the resource at that client defined URL.

The relevant specification for PUT and POST is RFC 2616 §9.5ff.

POST creates a child resource, so POST to /items creates a resources that lives under the /items resource. Eg. /items/1. Sending the same post packet twice will create two resources.

PUT is for creating or replacing a resource at a URL known by the client.

Therefore: PUT is only a candidate for CREATE where the client already knows the url before the resource is created. Eg. /blogs/nigel/entry/when_to_use_post_vs_put as the title is used as the resource key

PUT replaces the resource at the known url if it already exists, so sending the same request twice has no effect. In other words, calls to PUT are idempotent.

The RFC reads like this:


Note: PUT has mostly been used to update resources (by replacing them in their entireties), but recently there is movement towards using PATCH for updating existing resources, as PUT specifies that it replaces the whole resource. RFC 5789.

Update 2018: There is a case that can be made to avoid PUT. See "REST without PUT"

With “REST without PUT” technique, the idea is that consumers are forced to post new 'nounified' request resources. As discussed earlier, changing a customer’s mailing address is a POST to a new “ChangeOfAddress” resource, not a PUT of a “Customer” resource with a different mailing address field value.

taken from REST API Design - Resource Modeling by Prakash Subramaniam of Thoughtworks

This forces the API to avoid state transition problems with multiple clients updating a single resource, and matches more nicely with event sourcing and CQRS. When the work is done asynchronously, POSTing the transformation and waiting for it to be applied seems appropriate.

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    Or from the other side of the fence: PUT if the client determines the resulting resource's address, POST if the server does it. – DanMan Nov 28 '12 at 19:47
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    I think that this answer should be edited to make it more clear what @DanMan pointed in a very simple way. What I find the most valuable here is the note at the end, stating that a PUT should be used only for replacing the whole resource. – Hermes Nov 26 '13 at 22:37
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    PATCH isn't a realistic option for at least a few years, but I agree with the ideology. – crush Oct 3 '14 at 17:33
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    I'm trying to understand, but using PUT to create something would only make sense if the client knows for sure that the resource doesn't exist yet, right? Following the blog example, say you have created hundreds of blog posts in a couple of years, then accidentally pick the same title as you did for a post two years ago. Now you have gone and replaced that post, which wasn't intended. So using PUT to create would require the client to track what is taken and what is not, and could lead to accidents and unintended side effects, as well as having routes that do two entirely different things? – galaxyAbstractor Jan 30 '15 at 9:01
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    You are correct. PUTting a blog post at the same url as an existing one would cause an update to that existing post (although you could obviously check first with a GET). This indicates why it would be a bad idea to use just the title as the URL. It would however work anywhere there was a natural key in the data... which in my experience is rare. Or if you used GUIDs – Nigel Thorne Feb 3 '15 at 5:20



Can be performed with both PUT or POST in the following way:


Creates THE new resource with newResourceId as the identifier, under the /resources URI, or collection.

PUT /resources/<newResourceId> HTTP/1.1 


Creates A new resource under the /resources URI, or collection. Usually the identifier is returned by the server.

POST /resources HTTP/1.1


Can only be performed with PUT in the following way:


Updates the resource with existingResourceId as the identifier, under the /resources URI, or collection.

PUT /resources/<existingResourceId> HTTP/1.1


When dealing with REST and URI as general, you have generic on the left and specific on the right. The generics are usually called collections and the more specific items can be called resource. Note that a resource can contain a collection.


<-- generic -- specific -->

URI: website.com/users/john
website.com  - whole site
users        - collection of users
john         - item of the collection, or a resource

website.com  - whole site
users        - collection of users
john         - item of the collection, or a resource
posts        - collection of posts from john
23           - post from john with identifier 23, also a resource

When you use POST you are always refering to a collection, so whenever you say:

POST /users HTTP/1.1

you are posting a new user to the users collection.

If you go on and try something like this:

POST /users/john HTTP/1.1

it will work, but semantically you are saying that you want to add a resource to the john collection under the users collection.

Once you are using PUT you are refering to a resource or single item, possibly inside a collection. So when you say:

PUT /users/john HTTP/1.1

you are telling to the server update, or create if it doesn't exist, the john resource under the users collection.


Let me highlight some important parts of the spec:



Hence, creates a new resource on a collection.



Hence, create or update based on existence of the resource.


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    This post was helpful to me in understanding that POST adds "something" as a child to the given collection (URI), whereas PUT explicitly defines the "something" at the given URI location. – kwah Nov 23 '13 at 16:33
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    This is the best answer, here, I think: none of this "POST can update a resource" nonsense. I like your statement, "Update can only be performed with PUT". – Thomas May 28 '15 at 13:44
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    No, PUT is not for update or create. It is for replacing. Note that you can replace nothing with something for the effect of creating. – thecoshman Jun 8 '15 at 8:07
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    @7hi4g0 PUT is for for updating with a complete replacement, in other words, it replaces. You replace nothing with something, or something with a completely new something. PUT is not for making a minor change (unless you have the client make that minor change and provide the entire new version, even what is remaining the same). For partial modification, PATCH is the method of choice. – thecoshman Jun 8 '15 at 12:57
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    @thecoshman You could, but it wouldn't be too clear that create is also covered in there. In this case, it is better to be explicit. – 7hi4g0 Jun 9 '15 at 20:21

I'd like to add my "pragmatic" advice. Use PUT when you know the "id" by which the object you are saving can be retrieved. Using PUT won't work too well if you need, say, a database generated id to be returned for you to do future lookups or updates.

So: To save an existing user, or one where the client generates the id and it's been verified that the id is unique:

PUT /user/12345 HTTP/1.1  <-- create the user providing the id 12345
Host: mydomain.com

GET /user/12345 HTTP/1.1  <-- return that user
Host: mydomain.com

Otherwise, use POST to initially create the object, and PUT to update the object:

POST /user HTTP/1.1   <--- create the user, server returns 12345
Host: mydomain.com

PUT /user/12345 HTTP/1.1  <--- update the user
Host: mydomain.com
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    Actually, it should be POST /users. (Note that /users is plural.) This has the affect of creating a new user and making it a child resource of the /users collection. – DavidRR Dec 16 '14 at 13:54
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    @DavidRR to be fair, how to handle groups is another debate altogether. GET /users makes sense, it reads as you want, but I'd be ok with GET /user/<id> or POST /user (with payload for said new user) because it reads correctly 'get me users 5' is odd, but 'get me user 5' is more natural. I'd probably still fall down on the side of pluralisation though :) – thecoshman Jun 8 '15 at 7:57

POST means "create new" as in "Here is the input for creating a user, create it for me".

PUT means "insert, replace if already exists" as in "Here is the data for user 5".

You POST to example.com/users since you don't know the URL of the user yet, you want the server to create it.

You PUT to example.com/users/id since you want to replace/create a specific user.

POSTing twice with the same data means create two identical users with different ids. PUTing twice with the same data creates the user the first and updates him to the same state the second time (no changes). Since you end up with the same state after a PUT no matter how many times you perform it, it is said to be "equally potent" every time - idempotent. This is useful for automatically retrying requests. No more 'are you sure you want to resend' when you push the back button on the browser.

A general advice is to use POST when you need the server to be in control of URL generation of your resources. Use PUT otherwise. Prefer PUT over POST.

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    Sloppiness may have cause it to be commonly taught that there are only two verbs you need: GET and POST. GET to obtain, POST to change. Even PUT and DELETE were performed using POST. Asking what PUT really means 25 years later maybe a sign we learned it wrong at first. REST popularity drove people back to the basics where we must now unlearn past bad mistakes. POST was overused and now commonly taught incorrectly. Best part: "POSTing twice with the same data means create two identical [resources]". Great point! – maxpolk Sep 1 '14 at 19:36
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    How can you use PUT to create a record by the ID, like in your example user 5 if it doesn't exist yet? Don't you mean update, replace if already exists? or something – Luke Nov 28 '14 at 12:44
  • @Coulton: I meant what I wrote. You insert user 5 if you PUT to /users/5 and #5 does not exist yet. – Alexander Torstling Nov 28 '14 at 15:46
  • @Coulton: And PUT can also be used to replace the value of an existing resource in its entirety. – DavidRR Dec 16 '14 at 14:02
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    "Prefer PUT over POST"... care to justify that? – thecoshman Jun 8 '15 at 8:04

Use POST to create, and PUT to update. That's how Ruby on Rails is doing it, anyway.

PUT    /items/1      #=> update
POST   /items        #=> create
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    POST /items adds a new item to an already defined resource ('item'). It does not, as the answer says, "create a group." I don't understand why this has 12 votes. – David J. Jun 21 '12 at 5:26
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    This is a fair guideline, but an oversimplification. As the other answers mention, either method could be used for both create and update. – Brad Koch Mar 7 '13 at 15:55
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    I agree with the answer with a slight modification. Use POST to create and PUT to update the resource completely. For partial updates, we can use PUT or PATCH. Lets say we want to update the status of a group. We can use PUT /groups/1/status with the status is the request payload or PATCH /groups/1 with the details about the action in the payload – java_geek Oct 6 '14 at 6:26
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    It should also be made clear that PUT /items/42 is also valid for creating a resource, but only if the client has the privilege of naming the resource. (Does Rails allow a client this naming privilege?) – DavidRR Dec 16 '14 at 14:10
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    replace is better word for PUT patch is for update – Saurabh Chandra Patel Jan 20 '16 at 6:59

Both are used for data transmission between client to server, but there are subtle differences between them, which are:

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  • PUT i.e. take and put where it was.
  • POST as send mail in post office.

enter image description here

Social Media/Network Analogy:

  • Post on social media: when we post message, it creates new post.
  • Put(i.e. edit) for the message we already Posted.
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    So in summary: POST for inserts, PUT for updates – MobileMon Sep 22 '15 at 12:31
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    @MobileMon No, REST methods are not CRUD. – jlr Jan 8 '16 at 19:06
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    I'd say PUT for UPSERTS – Hola Soy Edu Feliz Navidad Nov 26 '18 at 11:45

REST is a very high-level concept. In fact, it doesn't even mention HTTP at all!

If you have any doubts about how to implement REST in HTTP, you can always take a look at the Atom Publication Protocol (AtomPub) specification. AtomPub is a standard for writing RESTful webservices with HTTP that was developed by many HTTP and REST luminaries, with some input from Roy Fielding, the inventor of REST and (co-)inventor of HTTP himself.

In fact, you might even be able to use AtomPub directly. While it came out of the blogging community, it is in no way restricted to blogging: it is a generic protocol for RESTfully interacting with arbitrary (nested) collections of arbitrary resources via HTTP. If you can represent your application as a nested collection of resources, then you can just use AtomPub and not worry about whether to use PUT or POST, what HTTP Status Codes to return and all those details.

This is what AtomPub has to say about resource creation (section 9.2):

To add members to a Collection, clients send POST requests to the URI of the Collection.

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    There's nothing wrong with allowing PUT to create resources. Just be aware that it means that the client provides the URL. – Julian Reschke Apr 7 '10 at 7:47
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    There's something very wrong with allowing PUT to create resources: the client provides the URL. That's the server's job! – Joshcodes Oct 29 '13 at 17:33
  • @Joshcodes It is not always the case that it is the server's job to create client ids. I have increasingly seen designs that let clients generate some sort of UUID as the resource id. This design lends itself in particular to increase scale. – Justin Ohms Feb 5 '17 at 18:26
  • @JustinOhms I agree with your point about client generated IDs (side note: all systems designed by me since circa 2008 require the client to create the ID as a UUID/Guid). That does not mean the client should specify the URL. – Joshcodes Feb 6 '17 at 18:24
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    Yes, if the resource already exists, use PUT. However, in nearly all cases, the resources should be created with POST and the client should not provide the URL. Roy Fielding agrees with this statement FWIW: roy.gbiv.com/untangled/2008/rest-apis-must-be-hypertext-driven – Joshcodes Feb 7 '17 at 1:26


At this point some people will argue that if RESTful-URL's are used, the client does knows the URL of the resource and therefore a PUT is acceptable. After all, this is why canonical, normalized, Ruby on Rails, Django URLs are important, look at the Twitter API … blah blah blah. Those people need to understand there is no such thing as a Restful-URL and that Roy Fielding himself states that:



The idea of a RESTful-URL is actually a violation of REST as the server is in charge of the URL structure and should be free to decide how to use it to avoid coupling. If this confuses you read about the significance of self discovery on API design.

Using POST to create resources comes with a design consideration because POST is not idempotent. This means that repeating a POST several times does not guarantee the same behavior each time. This scares people into using PUT to create resources when they should not. They know it's wrong (POST is for CREATE) but they do it anyway because they don't know how to solve this problem. This concern is demonstrated in the following situation:

  1. The client POST a new resource to the server.
  2. The server processes the request and sends a response.
  3. The client never receives the response.
  6. POST is not idempotent and the server …


10.4.10 409 Conflict




Replying with a status code of 409 Conflict is the correct recourse because:


Update based on release of RFC 7231 to Replace 2616

RFC 7231 is designed to replace 2616 and in Section 4.3.3 describes the follow possible response for a POST

If the result of processing a POST would be equivalent to a representation of an existing resource, an origin server MAY redirect the user agent to that resource by sending a 303 (See Other) response with the existing resource's identifier in the Location field. This has the benefits of providing the user agent a resource identifier and transferring the representation via a method more amenable to shared caching, though at the cost of an extra request if the user agent does not already have the representation cached.

It now may be tempting to simply return a 303 in the event that a POST is repeated. However, the opposite is true. Returning a 303 would only make sense if multiple create requests (creating different resources) return the same content. An example would be a "thank you for submitting your request message" that the client need not re-download each time. RFC 7231 still maintains in section 4.2.2 that POST is not to be idempotent and continues to maintain that POST should be used for create.

For more information about this, read this article.

  • Would a 409 Conflict response be the appropriate code for something like trying to create a new account with a username that already exists? I've been using 409 for versioning conflicts specifically, but after reading your answer, I wonder if it shouldn't be used for any "duplicate" requests. – Eric B. Jul 9 '14 at 4:43
  • @EricB. Yes, in the situation you describe "due to a conflict with the current state of the resource" the operation fails. Additionally, it is reasonable to expect that the user can resolve the conflict and the message body only needs to inform the user that the username already exists. – Joshcodes Jul 10 '14 at 13:25
  • @Joshcodes can you say more about the conflict resolution process? In this case, if the username already exists is the client expected to prompt the end user for a different username? What if the client is actually trying to use POST to change the username? Should PUT requests still be used for updating parameters, while POST is used for creating objects whether it be one at a time or several? Thanks. – BFar Jan 22 '15 at 22:41
  • @BFar2 if the username already exists then the client should prompt the user. To change the username, assuming the username is part of an already created resource which needs modified, PUT would be used because you are correct, POST is used for create, always and PUT for updates. – Joshcodes Jan 23 '15 at 1:09
  • explaining things using short and effective language is also a desirable skill – Junchen Liu Aug 24 '15 at 16:27

I like this advice, from RFC 2616's definition of PUT:


This jibes with the other advice here, that PUT is best applied to resources that already have a name, and POST is good for creating a new object under an existing resource (and letting the server name it).

I interpret this, and the idempotency requirements on PUT, to mean that:

  • POST is good for creating new objects under a collection (and create does not need to be idempotent)
  • PUT is good for updating existing objects (and update needs to be idempotent)
  • POST can also be used for non-idempotent updates to existing objects (especially, changing part of an object without specifying the whole thing -- if you think about it, creating a new member of a collection is actually a special case of this kind of update, from the collection's perspective)
  • PUT can also be used for create if and only if you allow the client to name the resource. But since REST clients aren't supposed to make assumptions about URL structure, this is less in the intended spirit of things.
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    "POST can also be used for non-idempotent updates to existing objects (especially, changing part of an object without specifying the whole thing" That's what PATCH is for – Snuggs May 4 '12 at 22:11

In short:

PUT is idempotent, where the resource state will be the same if the same operation is executed one time or multiple times.

POST is non-idempotent, where the resource state may become different if the operation is executed multiple times as compared to executing a single time.

Analogy with database query

PUT You can think of similar to "UPDATE STUDENT SET address = "abc" where id="123";

POST You can think of something like "INSERT INTO STUDENT(name, address) VALUES ("abc", "xyzzz");

Student Id is auto generated.

With PUT, if the same query is executed multiple times or one time, the STUDENT table state remains the same.

In case of POST, if the same query is executed multiple times then multiple Student records get created in the database and the database state changes on each execution of an "INSERT" query.

NOTE: PUT needs a resource location (already-resource) on which update needs to happen, whereas POST doesn't require that. Therefore intuitively POST is meant for creation of a new resource, whereas PUT is needed for updating the already existing resource.

Some may come up with that updates can be performed with POST. There is no hard rule which one to use for updates or which one to use for create. Again these are conventions, and intuitively I'm inclined with the above mentioned reasoning and follow it.

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    for PUT is similar to INSERT or UPDATE query – Eugen Konkov Aug 22 '16 at 9:25
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    actually PUT You can think of similar to "UPDATE STUDENT SET address = "abc" where id="123"; would be a statement for PATCH. "UPDATE STUDENT SET address = "abc", name="newname" where id="123" would be a correct analogy for PUT – mko Apr 12 '17 at 13:24
  • Put could also be used for INSERT. For example if you server detected you were trying to upload the same file multiple times, it would make your request idempotent. (No new file uploads are done). – kiwicomb123 Aug 20 '18 at 22:46

POST is like posting a letter to a mailbox or posting an email to an email queue. PUT is like when you put an object in a cubby hole or a place on a shelf (it has a known address).

With POST, you're posting to the address of the QUEUE or COLLECTION. With PUT, you're putting to the address of the ITEM.

PUT is idempotent. You can send the request 100 times and it will not matter. POST is not idempotent. If you send the request 100 times, you'll get 100 emails or 100 letters in your postal box.

A general rule: if you know the id or name of the item, use PUT. If you want the id or name of the item to be assigned by the receiving party, use POST.

POST versus PUT

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    No, PUT implies that you know the URL. If you only know the ID then POST with that ID to get the URL. – Joshcodes Oct 29 '13 at 17:35
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    The id is part of the URL, so yes, use PUT if you know the URL (which includes the id). – Homer6 Oct 29 '13 at 22:02
  • No, the URL is determined by the server and the ID is not necessarily part of the URL. Roy Fielding would tell you the same or you could just read his thesis. – Joshcodes Oct 29 '13 at 23:06
  • @Joshcodes, is that assuming REST? In a RESTful architecture, the item id is most definitely part of the URL, as in: /people/123. I like this site for REST: microformats.org/wiki/rest/urls – Beez Dec 26 '13 at 19:10
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    @Beez the mircoformats link suggests a good way for servers to structure their URLs but the server determines the URL. The client next-to-never does. See my answer or associated article if you don't understand this. – Joshcodes Jan 7 '14 at 17:11

New answer (now that I understand REST better):

PUT is merely a statement of what content the service should, from now on, use to render representations of the resource identified by the client; POST is a statement of what content the service should, from now on, contain (possibly duplicated) but it's up to the server how to identify that content.

PUT x (if x identifies a resource): "Replace the content of the resource identified by x with my content."

PUT x (if x does not identify a resource): "Create a new resource containing my content and use x to identify it."

POST x: "Store my content and give me an identifier that I can use to identify a resource (old or new) containing said content (possibly mixed with other content). Said resource should be identical or subordinate to that which x identifies." "y's resource is subordinate to x's resource" is typically but not necessarily implemented by making y a subpath of x (e.g. x = /foo and y = /foo/bar) and modifying the representation(s) of x's resource to reflect the existence of a new resource, e.g. with a hyperlink to y's resource and some metadata. Only the latter is really essential to good design, as URLs are opaque in REST -- you're supposed to use hypermedia instead of client-side URL construction to traverse the service anyways.

In REST, there's no such thing as a resource containing "content". I refer as "content" to data that the service uses to render representations consistently. It typically consists of some related rows in a database or a file (e.g. an image file). It's up to the service to convert the user's content into something the service can use, e.g. converting a JSON payload into SQL statements.

Original answer (might be easier to read):

PUT /something (if /something already exists): "Take whatever you have at /something and replace it with what I give you."

PUT /something (if /something does not already exist): "Take what I give you and put it at /something."

POST /something: "Take what I give you and put it anywhere you want under /something as long as you give me its URL when you're done."

  • But how can you use PUT to create a new resource if it doesn't exist, while your ID generation method is on Auto Increment ? Usually ORM's does auto generate the ID for you, like the way you want it to be in a POST for example. Does it mean that if you want to implement PUT the right way you have to change your id auto generation ? This is awkward if the answer is yes. – Roni Axelrad Sep 16 '18 at 15:28
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    @RoniAxelrad : PUT is like a database "INSERT OR UPDATE" statement where you are including the key in the statement, so only applicable where you can guarente no collisions. eg. your domain has a 'natural key' or you use a guid. POST is like inserting into a table with an auto incrementing key. You have to be told by the database what ID it got after it has been inserted. Note your "INSERT OR UPDATE" will replace any previous data if it existed. – Nigel Thorne Nov 26 '18 at 1:33
  • @NigelThorne Thanks for your answer. So if for example I'm trying to PUT a book id 10 with a URI: PUT books/10. If book id 10 does not exists, I should create a book with id 10 right? but I cannot control the creation ID numerator, because it's auto increment. what should I do in that situation ? – Roni Axelrad Nov 27 '18 at 20:50
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    @RoniAxelrad REST PUT to an ID that doesn't exist is a request to the server to create a resource. It's still up to the server to decide if it wants to allow that. The server is in charge. It can respond with "No. I'm not going to do that". You already do that if the user doesn't have enough permissions...etc. It's okay for the server to say "No". REST is a convention that lets us define the meaning of various types of request ... your server decides what to do with those requests based on your business logic :) Even if it says "no" it's still following REST :) – Nigel Thorne Dec 3 '18 at 7:03

Short Answer:

Simple rule of thumb: Use POST to create, use PUT to update.

Long Answer:


  • POST is used to send data to server.
  • Useful when the resource's URL is unknown


  • PUT is used to transfer state to the server
  • Useful when a resource's URL is known

Longer Answer:

To understand it we need to question why PUT was required, what were the problems PUT was trying to solve that POST couldn't.

From a REST architecture's point of view there is none that matters. We could have lived without PUT as well. But from a client developer's point of view it made his/her life a lot simpler.

Prior to PUT, clients couldn't directly know the URL that the server generated or if all it had generated any or whether the data to be sent to the server is already updated or not. PUT relieved the developer of all these headaches. PUT is idempotent, PUT handles race conditions, and PUT lets the client choose the URL.

  • 3
    Your short answer might be VERY wrong. HTTP PUT is free to be repeated by HTTP proxies. And so, if PUT is actually doing SQL INSERT it might fail second time, which means it would return different result and so it would not be IDEMPOTENT (which is the difference between PUT and POST) – Kamil Tomšík Apr 30 '18 at 17:27

Ruby on Rails 4.0 will use the 'PATCH' method instead of PUT to do partial updates.

RFC 5789 says about PATCH (since 1995):


"Edge Rails: PATCH is the new primary HTTP method for updates" explains it.


At the risk of restating what has already been said, it seems important to remember that PUT implies that the client controls what the URL is going to end up being, when creating a resource. So part of the choice between PUT and POST is going to be about how much you can trust the client to provide correct, normalized URL that are coherent with whatever your URL scheme is.

When you can't fully trust the client to do the right thing, it would be more appropriate to use POST to create a new item and then send the URL back to the client in the response.

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    I'm a bit late to this - but someone saying something similar on another website got it to click for me. If you're creating a resource and using an auto-incremented ID as it's "identifier" instead of a user assigned name, it should be a POST. – Ixmatus Feb 3 '12 at 18:51
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    This isn't quite right - PUT can still create a resource by referring to it with a non-canonical name, as long as in the response, the server returns a Location header that does contain the canonical resource name. – Ether Oct 19 '12 at 16:08
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    @Joshcodes don't forget that you can have many URIs referencing the same underlying resource. So what Ether said is sound advice, the client can PUT to a URL (that might be more semantic, like PUT /X-files/series/4/episodes/max) and the server respond with a URI that provides a short canonical unique link to that new resource (ie /X-Ffiles/episodes/91) – thecoshman Jun 8 '15 at 8:02
  • @thecoshman the issue is the concern for the URL structure does not belong to the client. Reading about self-discovery (also part of REST) may help make this clear. – Joshcodes Jun 8 '15 at 17:50
  • @Joshcodes then by that logic, a client should never use PUT to create as they shouldn't be concerned with with providing the URL. Well... unless the server provided a URL to PUT to if the client wants to put to it... something like "PUT /comments/new" and the server might respond "204 /comments/234532" but that seems a bit RPC to me, the client should just POST to /comments... – thecoshman Jun 9 '15 at 16:18

In a very simple way I'm taking the example of the Facebook timeline.

Case 1: When you post something on your timeline, it's a fresh new entry. So in this case they use the POST method because the POST method is non-idempotent.

Case 2: If your friend comment on your post the first time, that also will create a new entry in the database so the POST method used.

Case 3: If your friend edits his comment, in this case, they had a comment id, so they will update an existing comment instead of creating a new entry in the database. Therefore for this type of operation use the PUT method because it is idempotent.*

In a single line, use POST to add a new entry in the database and PUT to update something in the database.

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    If the comment is an object with property like user id, created date, comment-message, etc. and at the time of edit only comment-message is getting updated, PATCH should be done here? – Habeeb Perwad Aug 12 '17 at 10:47
  • PUT is used by FB to update the comment because an existing resource is being updated, and that is what PUT does (updates a resource). PUT happens to be idempotent, in contrast to POST. An HTTP verb being idempotent affects the error handling but does not dictate usage. See my answer for a more detail explanation: stackoverflow.com/questions/630453/put-vs-post-in-rest/… – Joshcodes Jun 19 '18 at 12:57

The most important consideration is reliability. If a POST message gets lost the state of the system is undefined. Automatic recovery is impossible. For PUT messages, the state is undefined only until the first successful retry.

For instance, it may not be a good idea to create credit card transactions with POST.

If you happen to have auto generated URI's on your resource you can still use PUT by passing a generated URI (pointing to an empty resource) to the client.

Some other considerations:

  • POST invalidates cached copies of the entire containing resource (better consistency)
  • PUT responses are not cacheable while POST ones are (Require Content-Location and expiration)
  • PUT is less supported by e.g. Java ME, older browsers, firewalls
  • This is incorrect. For POST, the state is also undefined only until the first successful retry. Then, either the server accepts the POST (message never arrived), throws a 409 conflict for a duplicate ID (message arrived, response was lost), or any other valid response. – Joshcodes Apr 24 '14 at 12:13
  • In general a useragent would not able to safely retry the POST operation since the POST operation gives no that guarantee that two operations would have the same effect as one. The term "ID" has nothing to do with HTTP. The URI identifies the resource. – Hans Malherbe Jul 25 '14 at 5:48
  • A useragent can "safely" retry a POST operation as many times as it wants. It will just receive a duplicate ID error (assuming the resource has an ID) or a duplicate data error (assuming that's an issue and the resource does not have IDs). – Joshcodes Jul 27 '14 at 2:10
  • Bangs head against wall. HTTP has no solution to the problem of reliability, and this is not well understood, not much discussed, and simply not catered for in the vast majority of web applications. @Joshcodes I have an answer to this question. I essentially agree with Hans. There's a problem. – bbsimonbb Jun 13 '18 at 8:21
  • @bbsimonbb, HTTP has a robust and well documented set of error responses. My answer to this question (stackoverflow.com/questions/630453/put-vs-post-in-rest/…) covers how to use http according to specification to achieve consistency. – Joshcodes Jun 19 '18 at 12:50


Create => HTTP PUT
Retrieve => HTTP GET
Update => HTTP POST



Based on the above idempotent definition, my take on using the HTTP PUT method versus using the HTTP POST method for REST services is: Use the HTTP PUT method when:


In both cases, these operations can be performed multiple times with the same results. That is the resource will not be changed by requesting the operation more than once. Hence, a true idempotent operation. Use the HTTP POST method when:



Do not directly correlate and map CRUD operations to HTTP methods for REST services. The use of an HTTP PUT method versus an HTTP POST method should be based on the idempotent aspect of that operation. That is, if the operation is idempotent, then use the HTTP PUT method. If the operation is non idempotent, then use the HTTP POST method.

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    Update => HTTP POST : POST is not for updating – Premraj Jan 30 '16 at 0:57

Readers new to this topic will be struck by the endless discussion about what you should do, and the relative absence of lessons from experience. The fact that REST is "preferred" over SOAP is, I suppose, a high-level learning from experience, but goodness we must have progressed from there? It's 2016. Roy's dissertation was in 2000. What have we developed? Was it fun? Was it easy to integrate with? To support? Will it handle the rise of smartphones and flaky mobile connections?

According to ME, real-life networks are unreliable. Requests timeout. Connections are reset. Networks go down for hours or days at a time. Trains go into tunnels with mobile users aboard. For any given request (as occasionally acknowledged in all this discussion) the request can fall in the water on its way, or the response can fall in the water on its way back. In these conditions, issuing PUT, POST and DELETE requests directly against substantive resources has always struck me as a little brutal and naive.

HTTP does nothing to ensure reliable completion of the request-response, and that's just fine because this is properly the job of network-aware applications. Developing such an application, you can jump through hoops to use PUT instead of POST, then more hoops to give a certain kind of error on the server if you detect duplicate requests. Back at the client, you then have to jump through hoops to interpret these errors, refetch, revalidate and repost.

Or you can do this: consider your unsafe requests as ephemeral single-user resources (let's call them actions). Clients request a new "action" on a substantive resource with an empty POST to the resource. POST will be used only for this. Once safely in possession of the URI of the freshly minted action, the client PUTs the unsafe request to the action URI, not the target resource. Resolving the action and updating the "real" resource is properly the job of your API, and is here decoupled from the unreliable network.

The server does the business, returns the response and stores it against the agreed action URI. If anything goes wrong, the client repeats the request (natural behaviour!), and if the server has already seen it, it repeats the stored response and does nothing else.

You will quickly spot the similarity with promises: we create and return the placeholder for the result before doing anything. Also like a promise, an action can succeed or fail one time, but its result can be fetched repeatedly.

Best of all, we give sending and receiving applications a chance to link the uniquely identified action to uniqueness in their respective environments. And we can start to demand, and enforce!, responsible behaviour from clients: repeat your requests as much as you like, but don't go generating a new action until you're in possession of a definitive result from the existing one.

As such, numerous thorny problems go away. Repeated insert requests won't create duplicates, and we don't create the real resource until we're in possession of the data. (database columns can stay not-nullable). Repeated update requests won't hit incompatible states and won't overwrite subsequent changes. Clients can (re)fetch and seamlessy process the original confirmation for whatever reason (client crashed, response went missing, etc.).

Successive delete requests can see and process the original confirmation, without hitting a 404 error. If things take longer than expected, we can respond provisionally, and we have a place where the client can check back for the definitive result. The nicest part of this pattern is its Kung-Fu (Panda) property. We take a weakness, the propensity for clients to repeat a request any time they don't understand the response, and turn it into a strength :-)

Before telling me this is not RESTful, please consider the numerous ways in which REST principles are respected. Clients don't construct URLs. The API stays discoverable, albeit with a little change in semantics. HTTP verbs are used appropriately. If you think this is a huge change to implement, I can tell you from experience that it's not.

If you think you'll have huge amounts of data to store, let's talk volumes: a typical update confirmation is a fraction of a kilobyte. HTTP currently gives you a minute or two to respond definitively. Even if you only store actions for a week, clients have ample chance to catch up. If you have very high volumes, you may want a dedicated acid-compliant key value store, or an in-memory solution.

  • Wont storing response be like maintaining a session? Which would cause (horizontal) scaling issues. – Saurabh Harwande Aug 21 '18 at 17:57

the origin server can create the resource with that URI

So you use POST and probably, but not necessary PUT for resource creation. You don't have to support both. For me POST is perfectly enough. So it is a design decision.

As your quote mentioned, you use PUT for creation of there is no resource assigned to an IRI, and you want to create a resource anyway. For example, PUT /users/123/password usually replaces the old password with a new one, but you can use it to create a password if it does not exist already (for example, by freshly registered users or by restoring banned users).

  • I think you've managed to provide one of the few good examples of how to use PUT, well done. – thecoshman Jun 8 '15 at 8:13

I'm going to land with the following:

PUT refers to a resource, identified by the URI. In this case, you are updating it. It is the part of the three verbs referring to resources -- delete and get being the other two.

POST is basically a free form message, with its meaning being defined 'out of band'. If the message can be interpreted as adding a resource to a directory, that would be OK, but basically you need to understand the message you are sending (posting) to know what will happen with the resource.

Because PUT and GET and DELETE refer to a resource, they are also by definition idempotent.

POST can perform the other three functions, but then the semantics of the request will be lost on the intermediaries such as caches and proxies. This also applies to providing security on the resource, since a post's URI doesn't necessarily indicate the resource it is applying to (it can though).

A PUT doesn't need to be a create; the service could error if the resource isn't already created, but otherwise update it. Or vice versa -- it may create the resource, but not allow updates. The only thing required about PUT is that it points to a specific resource, and its payload is the representation of that resource. A successful PUT means (barring interference) that a GET would retrieve the same resource.

Edit: One more thing -- a PUT can create, but if it does then the ID has to be a natural ID -- AKA an email address. That way when you PUT twice, the second put is an update of the first. This makes it idempotent.

If the ID is generated (a new employee ID, for example), then the second PUT with the same URL would create a new record, which violates the idempotent rule. In this case the verb would be POST, and the message (not resource) would be to create a resource using the values defined in this message.


In addition to differences suggested by others, I want to add one more.

In POST method you can send body params in form-data

In PUT method you have to send body params in x-www-form-urlencoded

Header Content-Type:application/x-www-form-urlencoded

According to this, you cannot send files or multipart data in the PUT method


The content type "application/x-www-form-urlencoded" is inefficient for sending large quantities of binary data or text containing non-ASCII characters. The content type "multipart/form-data" should be used for submitting forms that contain files, non-ASCII data, and binary data.

Which means if you have to submit

files, non-ASCII data, and binary data

you should use POST method

  • 2
    Why was this not upvoted? If true, this is a critical distinction is it not? – Iofacture Sep 29 '18 at 3:02
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    I faced it when implementing API for the profile update, which includes user profile pic upload. Then I tested it with the postman, Ajax, PHP curl and laravel 5.6 as backend. – Rohit Dhiman Sep 29 '18 at 6:54

The semantics are supposed be different, in that "PUT", like "GET" is supposed to be idempotent -- meaning, you can the same exact PUT request multiple times and the result will be as if you executed it only once.

I will describe the conventions which I think are most widely used and are most useful:

When you PUT a resource at a particular URL what happens is that it should get saved at that URL, or something along those lines.

When you POST to a resource at a particular URL, often you are posting a related piece of information to that URL. This implies that the resource at the URL already exists.

For example, when you want to create a new stream, you can PUT it to some URL. But when you want to POST a message to an existing stream, you POST to its URL.

As for modifying the properties of the stream, you can do that with either PUT or POST. Basically, only use "PUT" when the operation is idempotent - otherwise use POST.

Note, however, that not all modern browsers support HTTP verbs other than GET or POST.

  • What you describe POST as is actually how PATCH should behave. POST is supposed to mean something more akin to "append" as in "post to mailing list". – Alexander Torstling Nov 28 '14 at 15:57

Most of the time, you will use them like this:

  • POST a resource into a collection
  • PUT a resource identified by collection/:id

For example:

  • POST /items
  • PUT /items/1234

In both cases, the request body contains the data for the resource to be created or updated. It should be obvious from the route names that POST is not idempotent (if you call it 3 times it will create 3 objects), but PUT is idempotent (if you call it 3 times the result is the same). PUT is often used for "upsert" operation (create or update), but you can always return a 404 error if you only want to use it to modify.

Note that POST "creates" a new element in the collection, and PUT "replaces" an element at a given URL, but it is a very common practice to use PUT for partial modifications, that is, use it only to update existing resources and only modify the included fields in the body (ignoring the other fields). This is technically incorrect, if you want to be REST-purist, PUT should replace the whole resource and you should use PATCH for the partial update. I personally don't care much as far as the behavior is clear and consistent across all your API endpoints.

Remember, REST is a set of conventions and guidelines to keep your API simple. If you end up with a complicated work-around just to check the "RESTfull" box then you are defeating the purpose ;)


While there is probably an agnostic way to describe these, it does seem to be conflicting with various statements from answers to websites.

Let's be very clear and direct here. If you are a .NET developer working with Web API, the facts are (from the Microsoft API documentation), http://www.asp.net/web-api/overview/creating-web-apis/creating-a-web-api-that-supports-crud-operations:

1. PUT = UPDATE (/api/products/id)
2. MCSD Exams 2014 -  UPDATE = PUT, there are **NO** multiple answers for that question period.

Sure you "can" use "POST" to update, but just follow the conventions laid out for you with your given framework. In my case it is .NET / Web API, so PUT is for UPDATE there is no debate.

I hope this helps any Microsoft developers that read all comments with Amazon and Sun/Java website links.


If you are familiar with database operations, there are

  1. Select
  2. Insert
  3. Update
  4. Delete
  5. Merge (Update if already existing, else insert)

I use PUT for Merge and update like operations and use POST for Insertions.


Here's a simple rule:

PUT to a URL should be used to update or create the resource that can be located at that URL.

POST to a URL should be used to update or create a resource which is located at some other ("subordinate") URL, or is not locatable via HTTP.

  • 1
    PUT is not for update, it is for replace, note that to create you are replacing nothing with something. POST is absolutely not for update in any shape of form. – thecoshman Jun 8 '15 at 8:10
  • 1
    Does the http spec say that? Or are you basing your comment on something else? – Adam Griffiths Jul 10 '16 at 20:41
  • It's just common sense, how you update something when you don't know what it is you are updating? POST is for creating a new resource. – thecoshman Jul 27 '16 at 9:23
  • 2
    thecoshman -- you are abusing semantics here -- a replace can be an update if it is the same resource with a few differences. A replace is only valid for put if replace is used to change the same resource. Replacing with a new and different resource is invalid (remove old and add new?), especially if the 'new' resource doesn't have a natural ID. POST, OTOH, is something that can create, update, replace, and delete -- using post depends on whether or not there is a message to interpret, such as 'apply the discount', which may or may not change the resource depending on logic. – Gerard ONeill Dec 28 '16 at 16:54
  • As for your second comment -- how about you 'get' the resource, modify the fields you need to, and then put it back? Or how about if the resource comes from a different source but uses a natural ID (the external ID) -- put would naturally update the resource at the URL when the original data changed. – Gerard ONeill Dec 28 '16 at 16:56

In practice, POST works well for creating resources. The URL of the newly created resource should be returned in the Location response header. PUT should be used for updating a resource completely. Please understand that these are the best practices when designing a RESTful API. HTTP specification as such does not restrict using PUT/POST with a few restrictions for creating/updating resources. Take a look at http://techoctave.com/c7/posts/71-twitter-rest-api-dissected that summarizes the best practices.

  • For the most part, from reading through all this noise, you seem on the ball. I would say though, we should refer to PUT as the replace method, rather than the create/update. I think it better describes in one what it does. – thecoshman Jun 8 '15 at 8:15

protected by Bala R May 25 '11 at 3:44


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