Dictionary and language APIs provide word definitions, translations, synonyms, and linguistic data. Build vocabulary tools, writing assistants, or language learning applications.
| Name | Description | Auth | HTTPS | CORS | Status |
|---|---|---|---|---|---|
| Chinese Text Project | Online open-access digital library for pre-modern Chinese texts | none | Yes | unknown | unknown |
| Collins | Bilingual Dictionary and Thesaurus Data | apikey | Yes | unknown | unknown |
| Free Dictionary | Definitions, phonetics, pronounciations, parts of speech, examples, synonyms | none | Yes | unknown | unknown |
| Indonesia Dictionary | Indonesia dictionary many words | none | Yes | unknown | unknown |
| Merriam-Webster | Dictionary and Thesaurus Data | apikey | Yes | unknown | unknown |
| Oxford | Dictionary Data | apikey | Yes | no | unknown |
| Synonyms | Synonyms, thesaurus and antonyms information for any given word | apikey | Yes | unknown | unknown |
| Wiktionary | Collaborative dictionary data | none | Yes | yes | unknown |
| Wordnik | Dictionary Data | apikey | Yes | unknown | unknown |
| Words | Definitions and synonyms for more than 150,000 words | apikey | Yes | unknown | unknown |
4 of these APIs require no authentication — you can start making requests immediately without signing up for an account. Just pick one from the table above, check its documentation, and send your first request.
6 APIs in this category require a free API key. This usually means creating a free account on the provider's website and copying your key from the dashboard. The process typically takes less than a minute.
Not sure where to start? Look for APIs marked as "alive" in the status column — these were recently verified as working. For browser-based projects, check that the API supports CORS.
Yes, all APIs listed on API Bouncer have a free tier. Some are completely open (no sign-up needed), while others require a free account to get an API key. Free tiers typically have rate limits — check each API's documentation for specifics.
It depends on your needs. Consider: Do you need authentication or prefer no-auth? Does your project need CORS support for browser access? How many requests will you make? Start with a no-auth API to prototype quickly, then switch to a more feature-rich option if needed.
We run periodic health checks on all listed APIs. The "Status" column shows whether each API was responding at our last check. APIs marked as "alive" were recently verified. You can also test any API yourself using curl or our guides on testing APIs.
Most free APIs allow commercial use, but terms vary by provider. Always check the specific API's terms of service. Some APIs have separate free and commercial tiers with different rate limits.
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