Customize or customise? If you’ve seen both spellings, you’re not imagining the difference. Both are correct, but the preferred form depends on which variety of English you’re using.
The meaning is the same: to modify something so that it suits a particular person, purpose, preference, or situation.
The main difference is regional:
Customize → American English
Customise → British English
However, British English has an interesting detail: customize is also accepted and is increasingly common, particularly in technical, digital, and international contexts.
So the choice is less about right versus wrong and more about regional spelling and consistency.
The Quick Answer
Use customize if you’re following American English.
Use customise if you’re following traditional British English.
| Spelling | Main usage | Example |
|---|---|---|
| customize | American English | You can customize your profile. |
| customise | British English | You can customise your profile. |
Both mean exactly the same thing.
The website lets users customize their settings.
The website lets users customise their settings.
Neither sentence changes meaning.
What Does Customize Mean?
Customize is a verb meaning to change or adapt something according to a person’s particular needs or preferences.
For example:
You can customize the dashboard.
This means you can change the dashboard to suit your preferences.
Other examples include:
Customers can customize their orders.
I want to customize my phone settings.
The software allows users to customize the interface.
The noun is:
customization
And the adjective is:
customized
What Does Customise Mean?
Customise has exactly the same meaning as customize.
It is the traditional British English spelling.
Examples:
You can customise your homepage.
Customers can customise their meals.
The company offers customised solutions.
If you’re writing for readers in the UK, Ireland, Australia, or other markets that commonly follow British spelling conventions, customise may be the preferred choice.
Customize vs Customise: At a Glance
| Feature | Customize | Customise |
|---|---|---|
| Meaning | Modify to suit preferences | Modify to suit preferences |
| American English | Standard | Uncommon |
| British English | Accepted | Traditional/preferred |
| Pronunciation | Same | Same |
| Past tense | customized | customised |
| Noun | customization | customisation |
| Adjective | customized | customised |
The only difference is the letter z versus s.
Why Are There Two Spellings?
The difference comes from a broader spelling pattern between American and British English.
American English often prefers:
-ize
British English traditionally uses:
-ise
This gives us pairs such as:
organize / organise
realize / realise
recognize / recognise
customize / customise
However, the situation is more complicated than simply saying “American uses z and British uses s.”
Some British dictionaries and style guides accept -ize spellings as well. Oxford, for example, generally uses -ize spellings in its dictionary entries while noting British -ise variants. This means customize is not inherently “American-only.”
British English vs American English
This is the main distinction you need to remember.
American English
American English strongly favors:
customize
Examples:
You can customize your settings.
The app lets users customize their profiles.
We offer customized plans.
The z spelling is the normal choice in American writing.
British English
Traditional British usage commonly prefers:
customise
Examples:
You can customise your settings.
Customers can customise their orders.
We provide customised services.
But customize is also found in British English, especially in technical and international contexts.
Comparison Table
| Form | American English | British English |
|---|---|---|
| Present | customize | customise / customize |
| Past | customized | customised / customized |
| -ing form | customizing | customising / customizing |
| Noun | customization | customisation / customization |
| Meaning | Same | Same |
If you’re writing for a specific audience, consistency matters more than trying to mix forms.
Customize or Customise in Websites?
Both spellings are common online.
If your website follows American English, use:
Customize your experience
If it follows British English, use:
Customise your experience
The important thing is not to switch randomly between the two.
For example, a British-English website would look inconsistent if one page says:
Customise your profile
while another says:
Customize your profile
unless there is a deliberate reason for the difference.
Customize or Customise in Software?
You may see Customize more often in software interfaces because much of the technology industry uses American English.
For example:
Customize settings
Customize toolbar
Customize dashboard
Customize notifications
But British-localized software may use:
Customise settings
Customise toolbar
Both are grammatically correct.
The software’s language settings usually determine which spelling appears.
Pronunciation
Both words are pronounced the same.
Customize
Approximately:
KUS-tuh-mize
IPA:
/ˈkʌstəmaɪz/
Customise
Approximately:
KUS-tuh-mize
IPA:
/ˈkʌstəmaɪz/
The final s in customise is pronounced with a /z/ sound, not an /s/ sound.
So:
customize → /z/
customise → /z/
This is a spelling difference, not a pronunciation difference.
Word Origin
Both spellings come from custom.
Custom ultimately traces back through French to Latin consuetudo, referring to established practice, habit, or usage.
The verb customize/customise developed from the idea of adapting something according to a particular person’s customs, preferences, or requirements.
The modern sense became especially important with the growth of:
- manufacturing
- personalized products
- software
- websites
- digital services
- e-commerce
Today, the word is especially common in technology and online user experiences.
Grammar and Word Forms
Customize/customise is a regular verb.
Present tense
I customize my settings.
She customises her account.
Past tense
American:
She customized the design.
British:
She customised the design.
Present participle
American:
customizing
British:
customising
Noun
American:
customization
British:
customisation
Adjective
American:
customized
British:
customised
Common Collocations
The verb frequently appears with words such as:
- customize settings
- customize your profile
- customize your experience
- customize your order
- customize a product
- customize a website
- customize an interface
- customize a dashboard
- customize a plan
- customize a service
Examples:
Users can customize their profiles.
Customers can customize their orders.
You can customize the dashboard.
Customize vs Personalize
These words are related but not always identical.
Customize generally means modify something according to specific requirements or preferences.
Personalize often means make something specifically suited to an individual.
For example:
You can customize the layout.
This suggests changing the layout’s features or arrangement.
The website personalizes recommendations.
This suggests the website adapts recommendations to the individual user.
In everyday technology writing, however, the two can overlap.
Synonyms
Depending on context, synonyms for customize/customise include:
- personalize
- tailor
- adapt
- modify
- adjust
- alter
- configure
- individualize
- tailor-make
Examples:
You can customize the package.
You can tailor the package to your needs.
The best synonym depends on what is being changed.
Antonyms
There is no single perfect antonym, but useful opposites include:
- standardize
- generalize
- simplify
- leave unchanged
- keep standard
- leave as is
For example:
The company allows customers to customize their orders.
versus:
The company offers only standardized orders.
Common Mistakes
Mistake 1: Thinking one spelling is wrong
Both customize and customise are correct.
The difference is primarily regional.
Mistake 2: Using “customize” in British writing without considering style
Customize is not necessarily wrong in British English, but customise is the traditional spelling.
If you’re deliberately following British English, consistency usually favors customise.
Mistake 3: Writing “customize” with an extra “s”
❌ customisse
❌ customaise
✅ customize
Mistake 4: Writing “customise” with a “z”
❌ customizee
The correct forms are:
customize
customise
Mistake 5: Mixing derived forms
If you choose American English:
customize → customized → customizing → customization
If you choose British English:
customise → customised → customising → customisation
Try to keep the spelling system consistent.
A Simple Memory Trick
Think of the regional spelling pattern:
American → Z
British → S
So:
American: customize
British: customise
You can connect it with familiar pairs:
organize / organise
recognize / recognise
customize / customise
This makes the spelling easier to remember.
Everyday Examples
Technology
You can customize the app’s appearance.
British:
You can customise the app’s appearance.
Shopping
Customers can customize their shoes.
British:
Customers can customise their shoes.
Website
Sign in to customize your profile.
British:
Sign in to customise your profile.
Business
We create customized solutions for each client.
British:
We create customised solutions for each client.
Settings
Users can customize notification settings.
British:
Users can customise notification settings.
Practice Exercise
Choose customize or customise according to the variety requested.
1. American English
Users can _____ their profiles.
2. British English
Customers can _____ their orders.
3. American English
The software lets you _____ the dashboard.
4. British English
You can _____ the service to meet your needs.
5. American English
The company offers _____ packages.
Answers
- customize
- customise
- customize
- customise
- customized
For British English, the equivalent would be customised.
People Also Ask
Is it customize or customise?
Both are correct. Customize is the standard American spelling, while customise is the traditional British spelling.
Is customise British or American?
Customise is primarily associated with British English.
Is customize American English?
Yes. Customize is the standard spelling in American English.
Can British English use customize?
Yes. Customize is also accepted and appears in British English, although customise remains a common traditional choice.
Do customize and customise mean the same thing?
Yes. They have exactly the same meaning.
Is customization or customisation correct?
Both are correct regionally:
American: customization
British: customisation
Which is more common online: customize or customise?
Customize is particularly common on international websites and technology platforms because American English is widely used in the software industry. However, customise remains common on British-focused websites.
FAQs
Should I use customize or customise on my website?
Choose according to your target audience. Use customize for American English and customise if you are intentionally following traditional British English.
Is “customised” correct?
Yes. Customised is the British spelling of the past participle and adjective. American English uses customized.
Is “customising” correct?
Yes. It is the traditional British spelling of the present participle.
Is “customizing” correct?
Yes. Customizing is the standard American spelling and is also accepted in British English.
What is the noun of customize?
The noun is customization in American English and customisation in traditional British English.
Does customize mean personalize?
Often, yes, although customize can also imply configuring or modifying something, while personalize emphasizes making something suited to an individual.
Final Verdict
So, customize or customise?
Both are correct.
Customize = standard American English
Customise = traditional British English
The meaning doesn’t change, and both are pronounced the same.
If you’re writing for an American audience:
Customize your settings.
If you’re following traditional British English:
Customise your settings.
One final point is worth remembering: British English also accepts many -ize spellings, so customize is not automatically incorrect in British writing. What matters most is choosing a consistent style throughout your content.
Read More:
Hi, I’m Safdar Ali, an English language teacher with 26 years of teaching experience. My expertise is in English linguistics, grammar, and the differences between British and American English.
Through Gramiffy, I share practical, research-based guides to help students, writers, and English learners improve their language skills. My goal is to make English simple, accurate, and easy for everyone to understand.
