The smallest Javascript libraries on the internet ...

Popular Javascript libraries such as jQuery grew tremendously over the years.
To reduce bandwidth requirements, these libraries are usually minified and GZIP compressed.
Surprisingly, most Content Delivery Networks (CDNs) give you a quite bad level of GZIP compression.

Google's Zopfli (open source) is currently the best GZIP compressor and produces the smallest files.
It produces files fully compatible to the DEFLATE algorithm (used by GZIP) but in order to find even better compression
it is based on a random walk (trial-'n'-error). I run a brute-force search to find optimal Zopfli parameters.

That means: when decompressed by the browser, my files are 100% identical to the original minified versions.
There is no difference to the developer, to the administrator or to the end-user:
except my files are smaller and therefore load a tiny bit faster.

size(mine) < size(original)   but   content(mine) = content(original)

Everything you find on the website can be used in in non-commercial as well as commercial projects without any obligations
However, if you are a super-kind person, then please send me a short mail. Or a postcard. Or both.


My server analyzed these already minified and zipped projects and compressed them even further:
Project Author's Website Latest Version Best CDN's Size My Best Version Improvement Details Older Versions
AngularJS 1.7.8 61634 bytes 59486 bytes -2148 bytes (3.49%) in-depth info and 142 older versions
BackboneJS 1.4.0 8038 bytes 7746 bytes -292 bytes (3.63%) in-depth info and 24 older versions
Bootstrap 4.3.1 15434 bytes 14848 bytes -586 bytes (3.80%) in-depth info and 24 older versions
D3 5.9.2 80157 bytes 74945 bytes -5212 bytes (6.50%) in-depth info and 124 older versions
Dojo 1.15.0 (n/a) 53436 bytes (n/a) in-depth info and 94 older versions
Ember 3.0.0 (n/a) 113676 bytes (n/a) in-depth info and 107 older versions
jQuery 3.4.0 30908 bytes 29571 bytes -1337 bytes (4.33%) in-depth info and 75 older versions
Knockout 3.5.0 25223 bytes 24109 bytes -1114 bytes (4.42%) in-depth info and 17 older versions
lodash 4.17.11 24424 bytes 23340 bytes -1084 bytes (4.44%) in-depth info and 42 older versions
React 16.6.3 4699 bytes 4622 bytes -77 bytes (1.64%) in-depth info and 53 older versions
Socket.IO 2.2.0 15931 bytes 15086 bytes -845 bytes (5.30%) in-depth info and 37 older versions
ThreeJS 103 140276 bytes 134523 bytes -5753 bytes (4.10%) in-depth info and 53 older versions
UnderscoreJS 1.9.1 6428 bytes 6239 bytes -189 bytes (2.94%) in-depth info and 58 older versions
Vue 2.6.10 34098 bytes 32743 bytes -1355 bytes (3.97%) in-depth info and 101 older versions

On average, my files are 4.68% smaller than the smallest files you find on these major public content delivery networks:
Baidu, Boot, cdnhttps, cdnjs, fastcdn, Google, jsdelivr, Microsoft, Sina, unpkg and/or Yandex.

Not a single file from these CDNs is smaller or has the same size as my compressed files.

How To Use It

Select your desired library from the table above, for example jQuery 3.4.0, and either:
  1. download the smallest file and store it on your server

  2. hotlink to my server's copy
As mentioned before, after decompression my files are 100% identical to their original version.
The only difference is I spent much more time finding an (almost) optimal compression.

Fallback Solution

No matter which CDN you use, it's always a good idea to have a fallback in case the CDN is unreachable or - even worse - delisted your specific library.
All you have to do is to keep a copy of that library on your local server and add the following Javascript code:
<!-- try to download from CDN -->
<script src=""></script>
<!-- if failed, switch to local copy -->
<script>window.jQuery || document.write('<script src="local_server_path/jquery.min.js">\\x3C/script>')</script>

Please be aware that window.jQuery (last line) is specific to jQuery, for other libraries you have to use their dedicated main Javascript object:
Library Load Local Fallback
AngularJS <script>window.angular               || document.write('<script src="local_server_path/angular.min.js">\x3C/script>')</script>
BackboneJS <script>window.Backbone              || document.write('<script src="local_server_path/backbone.min.js">\x3C/script>')</script>
Bootstrap <script>$.fn.modal                   || document.write('<script src="local_server_path/bootstrap.min.js">\x3C/script>')</script>
D3 <script>window.d3                    || document.write('<script src="local_server_path/d3.min.js">\x3C/script>')</script>
Dojo <script>typeof(dojo) !== "undefined" || document.write('<script src="local_server_path/dojo.min.js">\x3C/script>')</script>
Ember <script>window.Ember                 || document.write('<script src="local_server_path/ember.min.js">\x3C/script>')</script>
jQuery <script>window.jQuery                || document.write('<script src="local_server_path/jquery.min.js">\x3C/script>')</script>
Knockout <script>window.ko                    || document.write('<script src="local_server_path/knockout.min.js">\x3C/script>')</script>
lodash <script>window._                     || document.write('<script src="local_server_path/lodash.min.js">\x3C/script>')</script>
React <script>window.React                 || document.write('<script src="local_server_path/react.min.js">\x3C/script>')</script>
ThreeJS <script>window.THREE                 || document.write('<script src="local_server_path/three.min.js">\x3C/script>')</script>
UnderscoreJS <script>window._                     || document.write('<script src="local_server_path/underscore.min.js">\x3C/script>')</script>

You can try another CDN instead of falling back to your local server, too.


I created this website as a hobby project because every time a byte is wasted, a kitten cries. Seriously ;-)

By the way: if you run a small website it's totally fine to hotlink to the compressed files on my server.
However, high-traffic websites should copy my files to their own server.
And in the best of all worlds, major CDNs would replace their (too) large versions ... well, I'm just dreaming.
Notes: pigz is a fast open source multi-threaded implementation of gzip written by one of the original authors of gzip.
However, when using compression level 11, pigz actually switches to the slower Zopfli algorithm and isn't multi-threaded anymore.
KrzyMOD's extensions to Zopfli offer the highest level of configuration and is therefore used for my brute-force search.
Ken Silverman wrote the closed-source KZIP compression program and Jonathon Fowler ported it to Linux.
Defluff was created by Joachim Henke; DeflOpt is a tool by Ben Jos Walbeehm.

website made by Stephan Brumme in 2015 and still improving in 2019.
all timestamps are displayed in central european time. see my changelog.
no flash, not even images or external css files - and everything squeezed into a single html file.
which was handsomely compressed before releasing it into the wild internet - obviously.

please visit my homepage and my blog, too.
email: minime (at)