Realise or Realize: What’s the Difference?

There are many spelling differences between American and British English. In some cases, the same word will be spelled one way in American English and another way in British English. There are times when this inconsistency is very confusing.

Realise and realize are two variants of the same word. One spelling is more common in American English, while the other is more common in British English.

Since both of these forms are accepted somewhere in the world, neither is technically wrong. Still, any time you are writing, you should consider your intended audience. This principle extends to spelling differences, as well.

You will want to use British spellings when writing for a primarily British audience, and American spellings if you are writing for a predominantly American audience.

What is the Difference Between Realise and Realize?

In this article, I will compare realise vs. realize. I will use each spelling in a sentence, and then I’ll show you a helpful trick to use when you can’t decide whether to use realise or realize in your own writing.

When to Use Realize

Definition of realize definition and definition of realise definitionWhat does realize mean? Realize is a verb that means to become aware of something or to bring something into being. The ize spelling is the sole spelling in American English and is also common in British English.

Realize is a regular verb and can be conjugated into various tenses by adding -d, -s, and -ing.

For example,

  • In the meeting, I realized that I had forgotten to brush my teeth this morning.
  • Do you realize that you have the most beautiful face?
  • Karen sold her shares of the electric company at $44.50, for a total realized gain of over six million dollars.
  • If it comes together, Concord could help banks streamline cumbersome operations, lower the costs of maintaining them, and realize billions of dollars in savings. –The Wall Street Journal

When to Use Realise

realise versus realize What does realise mean? Realise is a British variant spelling of this verb. It can be used in any of the same contexts as realize.

For example,

  • Too late, I realised that my chess opponent had caught me in the Würzburger trap.
  • I realise now that all of my efforts were in vain.
  • As the dawn broke, Enrique began to realise that the path to the top of the mountain would be more difficult than he had originally thought.
  • Elizabeth wanted to travel, to realise her dreams.
  • For the first time in my life I realised that sport actually makes sense and that the dedication and training are worth it. –The Irish Times

British Usage

While realise is comparatively more common in British English than American English, digital data on British books show that realize has been the predominant spelling in British English for almost 10 years.

British English:

how to spell realize

American English:

spelling of realise

These graphs tells a similar story of many British, American –ise, -ize spelling differences. Namely, British writers use both spelling with some frequency, while American writers have universally standardized around the -ize spellings.

Books like Folwer’s state that the Oxford University Press prefers ize spellings, while Cambridge University Press prefers ise spellings, which shows that both are used in British English.

Unless your workplace has a strong preference, however, it’s best to default to the ize spelling since the most people tend to use this spelling.

Trick to Remember the Difference

Define realize and define realiseHere is a helpful trick to remember realize vs. realise in your writing.

Realise and realize are alternative spellings of the same verb.

  • Realize should be used with American audiences.
  • Meanwhile, either spelling can be used with British audiences.

You can remember to use realize as the sole spelling for American audiences since it contains a z, like Arizona. Arizona is in America, so it will be easy to remember that realize is preferred in American English.


Is it realize or realise? Realise and realize are two spellings of the same verb, which means to become aware of something or to bring something into being.

  • Realise and realize both are accepted in British English.
  • Realize is the only accepted spelling in American English.

Since realize and Arizona both contain the letter z, it should be easy to choose realize when your readers will be American.

If you find yourself still having difficulty deciding whether to use realize or realise in your writing, you can always refer back to this article for a refresher.