API vs APL, What's the Difference?

Which to use

“API” and “APL” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#11,501
“API” frequency rank: #48,593
“APL” frequency rank: 60094
confusion score

Side-by-Side Comparison

Feature	API	APL
Definition	Initialism of active pharmaceutical ingredient.	Initialism of acute promyelocytic leukemia.

Letter map: API vs APL

Shared letters muted; letters that set API and APL apart highlighted. Shared run: 2.

3 ch

API

3 ch

APL

Corpus notes: API and APL

API and APL are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they differ by a single letter - i in “API” becomes l in “APL”. Our composite confusion score for this pair is 60094, derived from the frequency rank of both members and their visual similarity.

API is recorded at frequency rank #11,501, classified as anoun, pronounced /ˌeɪˌpiˈaɪ/. APL is at rank #48,593, tagged as anoun.

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 60094, this pair ranks #102,234 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of API vs APL

Shared letters: ap. Private to "API": i. Private to "APL": l.

"API" · 3 letters · shape VCV · "APL" · 3 letters · shape VCC

Frequently Asked Questions

Do "API" and "APL" mean the same thing in a sentence?

No. They differ by a single letter - i in “API” becomes l in “APL”, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.

Frequency check: "API" vs "APL" - which ranks higher?

"API" is the more common of the two: it sits at frequency rank #11,501 in our English list, against #48,593 for "APL". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Done with this confusable. These links stay specific to "API" and "APL".

Full dictionary entry for "API" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "APL" - compare definitions side by side with the headword page. Word entry
This pair ranks #102,234 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"API" and "APL" also get mixed up with nearby pairs, the highest-scored neighbour is "amb vs APL". Nearby pair

Confusion rank #102,234 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.