API vs au, What's the Difference?

Which to use

“API” is a noun and “au” is an intj - they look or sound alike but fill different roles in a sentence.

#19,027
“API” frequency rank: #7,821
“au” frequency rank: 26848
confusion score

Side-by-Side Comparison

Feature	API	au
Definition	Conjunto de especificaciones e implementación de comunicación entre componentes software. Se trata de de un conjunto de funciones o llamadas al sistema o bien un conjuto de clases y sus métodos cuyo propósito es ofrecer acceso a los servicios de un sistema.	Indica dolor.

Where the eye mixes API and au

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch

API

2 ch

Why the eye confuses API with au

These two trip readers on the page rather than in the ear: API is [ˈapi] while au is [ˈaw]. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (noun vs intj), which is usually the fastest check. Our composite confusion score for this pair is 26848, derived from the frequency rank of both members and their visual similarity.

API is recorded at frequency rank #19,027, classified as anoun, pronounced [ˈapi]. au is at rank #7,821, tagged as anintj, pronounced [ˈaw].

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 26848, this pair ranks #229,649 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of API vs au

Shared letters: a. Private to "API": ip. Private to "au": u.

"API" · 3 letters · shape VCV · "au" · 2 letters · shape VV

Frequently Asked Questions

Is swapping "API" for "au" ever safe?

No - they are not even the same part of speech. "API" is a noun and "au" an intj, so a sentence built for one is usually ungrammatical with the other.

Which is more common, "API" or "au"?

"au" is the more common of the two: it sits at frequency rank #7,821 in our Spanish list, against #19,027 for "API". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

Full dictionary entry for "API" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "au" - compare definitions side by side with the headword page. Word entry
This pair ranks #229,649 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
"API" and "au" also get mixed up with nearby pairs, the highest-scored neighbour is "API vs apis". Nearby pair

Confusion rank #229,649 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.