Datamuse

aid: datamuse
name: Datamuse
description: >-
  Datamuse operates a word-finding query engine and lexical search service for developers,
  educators, and creative-writing applications. The Datamuse API exposes a /words endpoint
  that finds words matching a rich combination of semantic, phonetic, orthographic, and
  vocabulary constraints (means-like, sounds-like, spelled-like, synonyms, antonyms,
  hypernyms, meronyms, triggers, rhymes, homophones, and more) plus a /sug autocomplete
  endpoint. Free for non-commercial use up to 100,000 requests per day with no API key
  required; commercial use, custom vocabularies, and higher rate limits are available
  via a paid commercial agreement. Datamuse also runs OneLook, OneLook Thesaurus,
  RhymeZone, Rimar.io, and CivicSearch — consumer-facing word search tools built on the
  same lexical infrastructure.
url: https://www.datamuse.com/api/
specificationVersion: '0.20'
created: '2026-05-28'
modified: '2026-05-29'
x-source: public-apis/public-apis
x-category: Open Source Projects
x-type: company
x-tier: 3
x-tier-reason: bulk-registered-from-public-apis
image: https://kinlane-productions.s3.amazonaws.com/apis-json/apis-json-logo.jpg
tags:
  - Word Finding
  - Lexical Search
  - Natural Language
  - Vocabulary
  - Synonyms
  - Antonyms
  - Rhymes
  - Phonetics
  - Semantic Search
  - Reverse Dictionary
  - Autocomplete
  - Wordplay
  - Creative Writing
  - Vocabulary Apps
  - Word Games
  - Linguistics
  - Open Source Projects
  - Public APIs
apis:
  - aid: datamuse:datamuse-api
    name: Datamuse API
    description: >-
      The Datamuse REST API exposes two operations covering word-finding (/words) and
      autocomplete suggestions (/sug). The /words endpoint accepts a rich combination of
      constraint parameters — semantic (ml, rel_syn, rel_ant, rel_trg, rel_spc, rel_gen,
      rel_com, rel_par, rel_jja, rel_jjb), phonetic (sl, rel_rhy, rel_nry, rel_hom,
      rel_cns), orthographic (sp with wildcards), and vocabulary (v=en|es) — plus
      ranking hints (topics, lc, rc) and result controls (max, md, qe, ipa). No
      authentication required for free non-commercial use up to 100k requests/day.
    humanURL: https://www.datamuse.com/api/
    baseURL: https://api.datamuse.com
    tags:
      - Word Finding
      - Lexical Search
      - Natural Language
    properties:
      - type: Documentation
        url: https://www.datamuse.com/api/
      - type: APIReference
        url: https://www.datamuse.com/api/
      - type: OpenAPI
        url: openapi/datamuse-openapi.yml
      - type: JSONSchema
        url: json-schema/datamuse-word-schema.json
      - type: JSONSchema
        url: json-schema/datamuse-suggestion-schema.json
      - type: JSONStructure
        url: json-structure/datamuse-word-structure.json
      - type: JSONStructure
        url: json-structure/datamuse-suggestion-structure.json
      - type: JSON-LD
        url: json-ld/datamuse-context.jsonld
      - type: Example
        url: examples/datamuse-getwords-example.json
      - type: Example
        url: examples/datamuse-getsuggestions-example.json
      - type: RateLimits
        url: rate-limits/datamuse-rate-limits.yml
      - type: Pricing
        url: plans/datamuse-plans-pricing.yml
    operations:
      - method: GET
        endpoint: /words
        summary: Find Words Matching Constraints
      - method: GET
        endpoint: /sug
        summary: Get Autocomplete Suggestions
common:
  - type: Website
    url: https://www.datamuse.com/
  - type: Documentation
    url: https://www.datamuse.com/api/
  - type: APIReference
    url: https://www.datamuse.com/api/
  - type: Pricing
    url: https://www.datamuse.com/api/
  - type: TermsOfService
    url: https://www.datamuse.com/api/
  - type: PrivacyPolicy
    url: https://www.datamuse.com/api/
  - type: Support
    url: https://www.datamuse.com/api/
  - type: SpectralRules
    url: rules/datamuse-rules.yml
  - type: Vocabulary
    url: vocabulary/datamuse-vocabulary.yml
  - type: NaftikoCapability
    url: capabilities/shared/datamuse-shared.yaml
  - type: NaftikoCapability
    url: capabilities/word-discovery.yaml
  - type: NaftikoCapability
    url: capabilities/rhyme-and-phonetics.yaml
  - type: NaftikoCapability
    url: capabilities/reverse-dictionary.yaml
  - type: NaftikoCapability
    url: capabilities/autocomplete.yaml
  - type: Plans
    url: plans/datamuse-plans-pricing.yml
  - type: RateLimits
    url: rate-limits/datamuse-rate-limits.yml
  - type: FinOps
    url: finops/datamuse-finops.yml
  - type: PublicAPIsListing
    url: https://github.com/public-apis/public-apis
  - type: SDK
    url: https://github.com/sjblair/Datamuse4J
  - type: SDK
    url: https://github.com/gmarmstrong/python-datamuse
  - type: SDK
    url: https://github.com/ansteh/datamuse
  - type: SDK
    url: https://github.com/ezefranca/datamuse-swift
  - type: SDK
    url: https://github.com/owenvoke/datamuse-php-api-wrapper
  - type: SDK
    url: https://github.com/kostaspt/go-datamuse
  - type: SDK
    url: https://github.com/slogemann1/datamuse-api-wrapper
  - type: SDK
    url: https://github.com/benhess02/DatamuseDotNet
  - type: SDK
    url: https://github.com/mosegontar/rubymuse
  - type: Tools
    url: https://github.com/lacausecrypto/datamuse-mcp
  - type: Tools
    url: https://github.com/pipeworx-io/mcp-datamuse
  - type: Tools
    url: https://github.com/bhayanak/datamuse-mcp-server
  - type: Tools
    url: https://github.com/pipeworx-io/mcp-words
  - type: Tools
    url: https://github.com/Eyalm321/multilingual-dictionary-mcp
  - type: Features
    data:
      - name: Means Like (ml)
        description: Reverse-dictionary semantic constraint finding words whose meaning matches an input string of any length.
      - name: Sounds Like (sl)
        description: Phonetic constraint returning words pronounced similarly to a given input using a text-to-phonemes algorithm.
      - name: Spelled Like (sp)
        description: Orthographic constraint with wildcard pattern matching (* for any chars, ? for a single char).
      - name: Predefined Relations (rel_*)
        description: Twelve lexical relations including synonyms, antonyms, hypernyms, hyponyms, holonyms, meronyms, triggers, frequent followers/predecessors, rhymes, near-rhymes, homophones, and consonant matches.
      - name: Context Ranking
        description: Topics, left-context (lc), and right-context (rc) parameters skew results toward a document theme or surrounding words.
      - name: Lexical Metadata (md)
        description: Optional metadata flags add definitions, parts of speech, syllable counts, pronunciations, and corpus frequency to each word.
      - name: Pronunciation Formats
        description: Default Arpabet pronunciations or IPA via the ipa flag, drawing on the CMU Pronouncing Dictionary.
      - name: Multilingual Vocabularies
        description: Default English (550k terms) and Spanish (500k terms) vocabularies; custom domain vocabularies available on request.
      - name: Autocomplete (/sug)
        description: Intelligent prefix suggestions with spelling correction and semantic fallback when exact matches are unavailable.
      - name: No API Key Required
        description: Free non-commercial use up to 100,000 requests per day without an account or API token; HTTPS and HTTP both supported.
      - name: Query Echo (qe)
        description: Prepends the result list with a record describing the query string, useful for one-shot word-metadata lookups.
  - type: UseCases
    data:
      - name: Vocabulary Building Apps
        description: Power flashcards, quizzes, and language-learning apps with synonyms, antonyms, and related-word lookups.
      - name: Creative Writing Tools
        description: Drive rhyme finders, thesaurus add-ins, and reverse-dictionary lookups for poetry, songwriting, and copywriting.
      - name: Word Games and Puzzles
        description: Generate clues, fill patterns with sp wildcards, and validate word lists for crosswords, hangman, and word ladders.
      - name: Autocomplete and Type-Ahead
        description: Provide intelligent prefix suggestions with spelling correction in search bars and form fields.
      - name: Educational Software
        description: Add definitions, syllable counts, and pronunciations to reading apps, ESL tools, and accessibility software.
      - name: Search Query Expansion
        description: Expand a user's search terms with semantically related words to improve recall in document or product search.
      - name: NLP Pre-Processing
        description: Look up word relations, frequencies, and pronunciations as features for downstream NLP pipelines.
      - name: Brand and Product Naming
        description: Combine sounds-like, means-like, and spelled-like constraints to brainstorm brand, domain, or product names.
  - type: Integrations
    data:
      - name: OneLook
        description: Datamuse's flagship word search engine indexing 10M+ words across 1000+ dictionaries; built on the same backend.
      - name: OneLook Thesaurus
        description: Reverse-dictionary and thesaurus product available on web, as a Google Docs add-on, and as an iOS/Mac app.
      - name: RhymeZone
        description: Rhyming dictionary and writing tool partnered with Merriam-Webster, available on web and mobile.
      - name: Rimar.io
        description: Spanish-language rhyming dictionary and thesaurus powered by Datamuse's Spanish vocabulary.
      - name: CivicSearch
        description: Local government meeting search engine covering 700+ jurisdictions across the US and Canada.
      - name: WordNet 3.0
        description: Princeton lexical database supplying synonyms, antonyms, hypernyms, hyponyms, holonyms, and meronyms.
      - name: CMU Pronouncing Dictionary
        description: Source for Arpabet pronunciations and the basis for phonetic constraints (sl, rel_rhy, rel_hom, rel_cns).
      - name: Google Books Ngrams
        description: Corpus underpinning frequency scores and the rel_jja, rel_jjb, rel_bga, rel_bgb statistical relations.
      - name: Wiktionary
        description: Source of definitions returned via the md=d metadata flag.
      - name: word2vec / Paraphrase Database
        description: Corpus and embedding sources contributing to means-like and trigger relations.
      - name: Obsidian Wordy Plugin
        description: Community plugin embedding Datamuse-powered thesaurus and reverse-dictionary directly into Obsidian.
      - name: Model Context Protocol Servers
        description: Multiple community MCP servers (lacausecrypto/datamuse-mcp, pipeworx-io/mcp-datamuse, bhayanak/datamuse-mcp-server) expose the API to LLM agents.
  - type: Solutions
    data:
      - name: Free Non-Commercial Tier
        description: Up to 100,000 requests per day with no API key, no signup, suitable for prototypes, hobby projects, research, and non-commercial education.
      - name: Commercial Plan
        description: Custom contract for production traffic in customer-facing applications, higher quotas, custom vocabularies, and SLA — pricing on request.
      - name: Custom Vocabulary Hosting
        description: Domain-specific term lists (medical, legal, gaming, internal jargon) hosted on Datamuse infrastructure with all standard relations.
maintainers:
  - FN: Kin Lane
    email: [email protected]