Realize vs. Realise
“Realize” and “realise” are regional spelling variants of the same verb. Cambridge notes the UK “realise” form; which spelling to publish depends on the regional or house style being followed, not on a difference in meaning.
Both spellings represent the same verb; choose “realize” or “realise” according to the intended regional or house style.
Key details
Choose the right form
| Audience / style | Use | Meaning |
|---|---|---|
| US-oriented style | realize | Regional spelling choice; meaning is unchanged. |
| UK-oriented style allowing -ise | realise | Regional/house-style spelling choice; meaning is unchanged. |
| Publication with a house dictionary | follow house style | Consistency is more important than switching within one document. |
Quick tests
Style test
Does the document specify US, UK, or another house spelling convention?
If yes: Use the spelling required by that convention.
If no: If no convention is specified, choose one accepted form and use it consistently.
Caveat: Do not present the variants as different verbs or meanings.
Examples
US style: I realize the deadline is close.
“Realize” fits the US-oriented spelling.
UK-oriented style: I realise the deadline is close.
“Realise” is a documented UK variant.
Further guidance
Core difference
The forms differ by spelling convention rather than core meaning.
Usage Boundary
Follow one regional or organizational style consistently; do not claim that the alternative spelling changes the verb’s meaning.
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.
- realize — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Regional spelling note for realize/realise