# optimisation vs optimization

> English confusable word pair

## The two words

### optimisation
*noun · frequency rank #40,370*
Alternative spelling of optimization.

### optimization
*noun · IPA /ˌɑptəmaɪˈzeɪʃən/ · frequency rank #11,927*
The design and operation of a system or process to make it as good as possible in some defined sense.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/optimisation-vs-optimization