API

/ˌeɪˌpiˈaɪ/

//ˌeɪˌpiˈaɪ// noun

By · According to Wiktionary data (CC BY-SA) ·

"api" is a 3-letter English headword indexed on PlainSpell.

The verdict

“API” sits in 20 confusable pairs (corpus #11,501) as a noun. The look-alike neighbours are the real trap.

#11,501
frequency rank, English
3,931
“A” headwords
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Initialism of active pharmaceutical ingredient.

Corpus desk

Index EN-api · API · English

API · rank #11,501 · 0 variants · 20 confusables

  • FREQ-MID #11,501
  • LEN-MID 3 letters
  • VOW-2 2 vowels
  • CONFUS-HIGH 20 pairs
  • VAR-0 0 variants
  • BOOK-MID 3,931
  • PHOTO-FINISH ale

Nearest frequency peer: ale (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Frequency neighbours of confusable “API”

Peers at similar corpus weight, separate from look-alike pairs below

corpus weight

What this shows Bars place “API” against nearest ranked English headwords, not a reprint of the confusable-pair desk.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

API vs as
0% similar
API vs at
0% similar
API vs aw
0% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for API
PropertyValue
HeadwordAPI
LanguageEnglish
Part of speechNoun
IPA/ˌeɪˌpiˈaɪ/
Letters3
Frequency rank#11,501
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Corpus rank beside confusables of “API”

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).APIlands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Same rarity band neighbours include “ale” (#11,500), “archaeological” (#11,502), “addict” (#11,499). Among 3,931 “A” headwords, “API” is #11,501. Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for API is neighbouring look-alikes ("as", "at", …), not just typos; it is anoun pronounced /ˌeɪˌpiˈaɪ/. Frequency #11,501 among 3,931 “A” headwords. 5 recorded senses keep meaning in play.

The misspelling generator found no plausible variants for API, since its letter pattern doesn't lend itself to common typo substitutions. It also participates in 20 confusable-pair relationships, "as", "at", "aw", and more, where similar look or sound leads writers to substitute one word for another in context.

No borrowing history is documented for this entry, so its spelling is easiest to reason about phoneme by phoneme, absent a documented history. The correct English form is API, spelled A-P-I.

Definition

  1. 1
    Initialism of active pharmaceutical ingredient.
  2. 2
    Initialism of application programming interface.
  3. 3
    Initialism of Asian and Pacific Islander.
  4. 4
    Initialism of advanced primer ignition.
  5. 5
    Initialism of armor-piercing incendiary.

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "API"?
"API" is spelled A-P-I. The IPA pronunciation is /ˌeɪˌpiˈaɪ/.
What does "API" mean?
As a noun, "API" means: Initialism of active pharmaceutical ingredient.
What words are commonly confused with "API"?
"API" is commonly confused with "as", "at", "aw". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "API"?
The IPA (International Phonetic Alphabet) transcription for "API" is /ˌeɪˌpiˈaɪ/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What language does "API" come from?
"API" is a English word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "API", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

ale#11,500uni#11,489sol#11,466gin#11,550

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

Source: FrequencyWords open word-frequency list