Many people search for “customise or customize” because both spellings appear correct, yet they are used in different places.
You may see customize on websites, apps, and software settings, while customise often appears in British documents and international content.
This creates confusion for students, content writers, developers, and professionals who want to use the correct spelling.
You might wonder: Is one spelling wrong? Or does it depend on the country? The answer is simple but important.
This is not a spelling mistake it’s a British vs American English difference. Using the wrong version for your audience can make your writing feel inconsistent or unprofessional.
This article clears the confusion completely. You’ll get a quick answer, learn the origin of the word, understand why two spellings exist, compare British and American rules with examples, and get clear advice on which spelling to use.
By the end, you’ll confidently know when to use customise and when to use customize.
Customise or Customize : Quick Answer
Both spellings are correct, depending on the type of English you are using.
- Customize → American English ✅
- Customise → British English ✅
Examples:
- 🇺🇸 You can customize your profile.
- 🇬🇧 You can customise your profile.
The meaning is exactly the same in both cases.
The Origin of Customise or Customize
The word comes from custom, meaning a traditional practice or personal preference. The verb form developed to mean to modify something according to specific needs.
The spelling difference exists because of historical spelling reforms:
- American English (influenced by Noah Webster) favors -ize
- British English commonly uses -ise
Both spellings share the same Greek root -izein, meaning to make or form. This is why neither spelling is wrong they simply follow different standards.
British English vs American English Spelling
This difference applies to many verbs ending in -ise / -ize.
Key Rule
- American English → -ize
- British English → -ise (though -ize is also acceptable in some UK publications)
Comparison Table
| English Variety | Preferred Spelling | Example |
| American English | Customize | Customize your settings |
| British English | Customise | Customise your settings |
| Canadian English | Customize / Customise | Both accepted |
| Australian English | Customise | Customise your design |
| Global English | Depends on audience | Stay consistent |
Which Spelling Should You Use?
Choose based on your audience and platform.
- US audience / tech products: Customize
- UK audience / education: Customise
- International audience: Choose one style and stay consistent
- Academic writing: Follow your style guide
💡 Tip:
Never mix customise and customize in the same document.
Common Mistakes with Customise or Customize
Here are frequent errors:
- ❌ Mixing both spellings in one article
✅ Use one spelling consistently - ❌ Thinking one spelling is incorrect
✅ Both are correct - ❌ Using British spelling for US brands
✅ Use customize for American companies
Learn More : Miter or Mitre: Which One Should You Use?
Customise or Customize in Everyday Examples
Emails
- 🇺🇸 “You can customize your order.”
- 🇬🇧 “You can customise your order.”
Websites & Apps
- “Users can customize/customise their dashboard.”
Business Writing
- “We customise solutions for our clients.”
Social Media
- “Just customized my phone layout 📱”
Formal Writing
- “The system allows users to customise preferences.”
Customise or Customize : Google Trends & Usage Data
Search data shows:
- Customize dominates searches in the United States
- Customise is more common in the UK, Australia, and India
The confusion is common among:
- ESL learners
- Content writers
- Software and UX designers
Both spellings appear frequently in professional and academic content, depending on region.
Comparison Table: Customise vs Customize
| Word | English Type | Correct Usage |
| Customize | American English | ✅ Correct |
| Customise | British English | ✅ Correct |
FAQs: Customise or Customize
1. Is customise incorrect?
No. It is correct in British English.
2. Is customize incorrect?
No. It is correct in American English.
3. Which spelling should I use in exams?
Use the spelling taught in your syllabus.
4. Can British English use “customize”?
Yes, but customise is more common.
5. Which spelling is used in software?
Mostly customize, due to US tech influence.
6. Does pronunciation change?
No. Both are pronounced the same.
7. Are customise and customize the same meaning?
Yes. The meaning is identical.
Conclusion
The confusion between customise or customize is understandable, but the solution is simple. Both spellings are correct, and the choice depends on whether you are using British English or American English.
Use customize for American audiences and most tech-related content. Use customise for British, Australian, and Commonwealth readers. The most important rule is consistency mixing both spellings in one document can weaken your writing.
Once you understand this spelling difference, you can write with confidence for any audience. Mastering pairs like customise vs customize helps you sound more professional and accurate in global English.
I am Bryan A. Garner, an American writer and editor focused on English usage, grammar, and word choice.
I am best known for Garner’s Modern English Usage, a reference book widely used by writers, editors, and legal professionals.
My work centers on clarity, precision, and resolving confusing word comparisons in modern English.
