Capitalize vs. Capitalise
“Capitalize” and “capitalise” are regional spelling variants of the same verb. Cambridge records the British “capitalise” variant, so writers should choose the form that matches their regional or publication style and use it consistently.
“Capitalize” and “capitalise” mean the same thing; select the spelling required by your regional or house style.
Key details
Choose the right form
| Meaning / situation | Construction | Decision |
|---|---|---|
| US-oriented spelling | capitalize | use in US house style |
| UK-oriented spelling | capitalise | use when UK spelling is required or preferred |
Quick tests
Regional-style test
Is the document following US spelling conventions?
If yes: Use “capitalize.”
If no: Use “capitalise” for a UK-oriented style that prefers -ise forms.
Caveat: The spellings do not mark different meanings; preserve the governing regional or house style.
Examples
Capitalize the first word of the heading.
“Capitalize” is standard US spelling.
Capitalise the first word of the heading.
“Capitalise” is an established UK spelling.
Choose one regional spelling system and use it consistently.
Consistency is the editing decision, not a universal correctness claim.
Further guidance
Core difference
The spelling varies regionally; there is no separate general meaning created by changing -ize to -ise here.
Usage Boundary
Keep the chosen spelling consistent across the document or product instead of alternating forms without a style reason.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- capitalize — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Regional spelling note for capitalize/capitalise