Datamuse

Overview

Datamuse is a word-finding query engine: find words that rhyme, mean the same, sound similar, or fit a spelling pattern — with frequency scores and part-of-speech tags. Free, keyless, and a joy for writers, word games, and search-as-you-type features.

Quick Start

Words similar in meaning (verified live):

curl "https://api.datamuse.com/words?ml=happy&max=3"

[
  {"word": "pleased", "score": 40004395, "tags": ["syn", "adj"]},
  {"word": "blissful", "score": 40004156, "tags": ["syn", "adj"]},
  {"word": "joyful", "score": 39978682, "tags": ["syn", "adj"]}
]

Rhymes:

curl "https://api.datamuse.com/words?rel_rhy=cat"

Sounds like:

curl "https://api.datamuse.com/words?sl=bananna"

Spelling pattern (crossword help):

curl "https://api.datamuse.com/words?sp=m?n??"

Words for autocomplete suggestions:

curl "https://api.datamuse.com/sug?s=interes"

Key parameters

Authentication

None — keyless.

Rate Limits & Notes

• Free; the docs ask for no more than ~1 request/second from a single IP (bursts are fine).
• Results include score (frequency-based) and tags (part of speech, syn, n…) — use them for ranking and filtering.
• sug endpoint is ideal for type-ahead search boxes.

FAQ

Is Datamuse free? Yes — free and keyless (≈1 req/s per IP).

Can I use it for autocomplete? Yes — the /sug endpoint returns prefix suggestions.

Do results include part of speech? Yes — the tags array includes PoS tags like adj, n, v.