Collins vs Words

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.

WordsAPI is a RapidAPI-hosted REST dictionary/thesaurus returning JSON definitions, synonyms, antonyms, rhymes, pronunciations, and word-frequency data across more than 150,000 English words — its own docs still show code samples calling the deprecated `wordsapiv1.p.mashape.com` host with an `X-Mashape-Key` header, but that legacy domain now refuses every request and a current RapidAPI key against the live `.p.rapidapi.com` proxy is required instead. A live unauthenticated request against that real proxy host returned a reflected `access-control-allow-origin` header plus `access-control-allow-credentials: true`, confirming CORS; its free tier covers 2,500 requests/day before paid plans starting at $10/month raise the ceiling to 25,000+/day.