APIvsapptWhat's the difference?

Quick tell: API is a noun, appt is a verb, so they fill different roles in a sentence.

Which to use

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

#11,501
“API” frequency rank
#48,065
“appt” frequency rank
59566
confusion score

Side-by-Side Comparison

Feature API appt
Definition Initialism of active pharmaceutical ingredient. Abbreviation of appoint.

Letter map: API vs appt

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

3 ch
API
4 ch
appt

Role in the sentence - API and appt

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: API is anoun and apptaverb. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 59566, 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/. appt is at rank #48,065, tagged as averb.

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 59566, this pair ranks #105,386 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of API vs appt

Shared letters: ap. Private to "API": i. Private to "appt": t.

"API" · 3 letters · shape VCV  ·  "appt" · 4 letters · shape VCCC

Known mistypes of this pair

  • apptapptt · aptp · papt

Frequently Asked Questions

Is swapping "API" for "appt" ever safe?
No - they are not even the same part of speech. "API" is a noun and "appt" a verb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "API" or "appt"?
"API" is the more common of the two: it sits at frequency rank #11,501 in our English list, against #48,065 for "appt". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pair "API" vs "appt" is on the table, pick a follow-up below.

  • Full dictionary entry for "API" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "appt" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #105,386 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "API" and "appt" also get mixed up with nearby pairs, the highest-scored neighbour is "APL vs appt". Nearby pair
  • Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes

Confusion rank #105,386 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list