Dictionaries · head-to-head
Collins vs Free Dictionary
Collins' REST API serves the publisher's monolingual English and bilingual dictionary, thesaurus, translation and audio-pronunciation data used on collinsdictionary.com, with separate JSON and XML response representations for each resource. A live unauthenticated request against the real gateway returned a genuine application-level "NoAccessKey" 403 rather than a Cloudflare challenge, confirming the API Key requirement and that the service itself is fully live. Its own pricing page grants up to 5,000 calls/month free before metered tiers (from £50/month) kick in at higher volumes.
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.
| Collins | Free Dictionary | |
|---|---|---|
| Authentication | API Key | None |
| Pricing | freemium | free |
| Formats | JSON, XML | JSON |
| CORS | no | yes |
| HTTPS | Yes | Yes |
Free Dictionary needs no API key, while Collins requires API Key — pick Free Dictionary to start without signup.