Best Dictionaries APIs in 2026

The top 15 of 15 free Dictionaries APIs, ranked by how easy they are to start with (API key, HTTPS, CORS), how reliable they are in our daily health checks, and what developers rate them. Random Lexicon API takes the top spot.

Last tested Oct 24, 2026 · Rankings update daily

1
Random Lexicon API
Online · 592 ms
Random words and definitions using optional filters.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
2
Wiktionary API
Online · 942 ms
Collaborative dictionary data. A free dictionaries API by Wiktionary.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
3
WordSoHard API
Online · 500 ms
Word definitions with Scrabble validity and tile score in one call, built for word games.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
4
Free Dictionary API
Online · 620 ms
Definitions, phonetics, pronunciations, parts of speech, examples, synonyms.
- No API key needed
- HTTPS
No authHTTPSCORS ?
5
Chinese Text Project API
Online · 860 ms
Online open-access digital library for pre-modern Chinese texts.
- No API key needed
- HTTPS
No authHTTPSCORS ?
6
SayItVid API
Online · 749 ms
English video pronunciation search with timestamps, IPA phonetics and subtitle context.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS
7
Collins API
Online · 61 ms
Bilingual Dictionary and Thesaurus Data.
- Fast: 61 ms response
- HTTPS
apiKeyHTTPSCORS ?
8
Synonyms API
Online · 954 ms
Synonyms, thesaurus and antonyms information for any given word.
- HTTPS
apiKeyHTTPSCORS ?
9
Merriam-Webster API
Online · 690 ms
Dictionary and Thesaurus Data. A free dictionaries API by dictionaryapi.com.
- HTTPS
apiKeyHTTPSCORS ?
10
Oxford API
Online · 1071 ms
The Oxford Dictionaries API gives you access to our world-renowned dictionary data, including definitions, translations, synonyms, and audio pronunciations.
- HTTPS
apiKeyHTTPSNo CORS
11
Wordnik API
Online · 1565 ms
The Wordnik API: All the words.
- HTTPS
apiKeyHTTPSCORS ?
12
Words API
Online · 673 ms
Definitions and synonyms for more than 150,000 words.
- HTTPS
apiKeyHTTPSCORS ?
13
Chinese Character Web API
Online · 505 ms
Chinese character definitions and pronunciations.
- No API key needed
No authNo HTTPSNo CORS
14I
Indonesia Dictionary API
Last check failed
Indonesia dictionary many words. A free dictionaries API by new-kbbi-api.herokuapp.com.
- No API key needed
- HTTPS
No authHTTPSCORS ?
15L
Lingua Robot API
Last check failed
Word definitions, pronunciations, synonyms, antonyms and others.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS

Dictionaries APIs compared

Top Dictionaries APIs compared
API	API key	HTTPS	CORS	Uptime	Response	Rating
Random Lexicon	No	Yes	Yes	Up	592 ms	Not rated
Wiktionary	No	Yes	Yes	Up	942 ms	Not rated
WordSoHard	No	Yes	Yes	Up	500 ms	Not rated
Free Dictionary	No	Yes	Unknown	Up	620 ms	Not rated
Chinese Text Project	No	Yes	Unknown	Up	860 ms	Not rated
SayItVid	Required	Yes	Yes	Up	749 ms	Not rated
Collins	Required	Yes	Unknown	Up	61 ms	Not rated
Synonyms	Required	Yes	Unknown	Up	954 ms	Not rated
Merriam-Webster	Required	Yes	Unknown	Up	690 ms	Not rated
Oxford	Required	Yes	No	Up	1071 ms	Not rated

More Dictionaries APIs

Best Dictionaries API FAQ

What is the best free Dictionaries API in 2026?

Based on access, reliability and developer ratings, the top free Dictionaries APIs right now are Random Lexicon API, Wiktionary API and WordSoHard API. Random Lexicon API ranks first. Rankings update daily from health checks of all 15 Dictionaries APIs in the directory.

What is the best Dictionaries API without an API key?

Random Lexicon API, Wiktionary API and WordSoHard API need no API key, so you can call them without signing up. 7 of the 15 ranked Dictionaries APIs are keyless.

Which Dictionaries API works from the browser?

Random Lexicon API, Wiktionary API and WordSoHard API support CORS over HTTPS, so front-end JavaScript can call them directly without a proxy.

How are these APIs ranked?

Each API gets a score from: no API key (+), HTTPS (+), CORS support (+), 30-day uptime and response time from our daily health checks, and ratings from developers on this site. APIs that failed three checks in a row are left out until they recover.