Free Dictionary API vs Merriam-Webster Dictionary API
Free API comparison
| Free Dictionary API | Merriam-Webster Dictionary API | |
|---|---|---|
| Category | Language and text | Language and text |
| API key | Not needed | Needed, free |
| Pricing | Free and open source, no key needed. | Free with a free API key for non-commercial use, up to 1,000 queries a day for two reference APIs; commercial use needs Merriam-Webster's approval. |
| Commercial use | Not stated | Not on the free plan |
| From the browser | Yes (CORS) | Yes (CORS) |
| Formats | JSON | JSON |
| Interface | REST, HTTP-GET | HTTP-GET |
| Provider | dictionaryapi.dev | dictionaryapi.com |
| Last checked | Working on October 31st, 2026 | Not stated |
| MCP server | No | No |
Which one to choose
The Free Dictionary API needs no key and is open source: one request per English word gives definitions, phonetics, audio links, examples, synonyms and antonyms. Merriam-Webster needs a free key, is for non-commercial use up to 1,000 queries a day, and adds etymology and its thesaurus. Start with the Free Dictionary API; use Merriam-Webster when you need its dictionary by name.
Each service's own page has its full description, a code example and what visitors report: Free Dictionary API, Merriam-Webster Dictionary API.