Dictionaries · head-to-head
Free Dictionary vs Oxford
Free Dictionary API is a keyless REST service built and maintained by a solo developer, returning English word definitions, phonetic spellings, audio pronunciation clips, parts of speech, usage examples, and synonyms/antonyms as plain JSON from a single GET request. It now serves more than 10 million requests a month and is funded entirely through voluntary donations rather than any paid tier.
Oxford Dictionaries API (Oxford Languages) exposes definitions, translations, and lexical metadata sourced from Oxford University Press's own databases across dozens of languages, authenticated with an app ID/key pair from its developer portal. New accounts start on a free Sandbox tier that emulates the live API for evaluation before moving to paid production plans, with custom Enterprise licensing available from an annual per-language fee.
| Free Dictionary | Oxford | |
|---|---|---|
| Authentication | None | API Key |
| Pricing | free | freemium |
| Formats | JSON | JSON |
| CORS | yes | no |
| HTTPS | Yes | Yes |
Free Dictionary needs no API key, while Oxford requires API Key — pick Free Dictionary to start without signup.