# API vs AU

> English confusable word pair

## The two words

### API
*noun · IPA /ˌeɪˌpiˈaɪ/ · frequency rank #11,501*
Initialism of active pharmaceutical ingredient.

### AU
*noun · frequency rank #6,867*
Initialism of alopecia universalis.

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