Wordnik vs Words

Wordnik's REST API returns word definitions aggregated from multiple published dictionaries alongside example sentences, pronunciations, related words, and corpus-derived frequency data, documented through an interactive Swagger UI. Every developer gets a free Basic plan (100 calls/hour, with an explicit nonprofit/research allowance) before paid Hobby, Pro, and Enterprise tiers raise the ceiling up to 45,000 calls/hour -- revenue that funds Wordnik's nonprofit mission to document the English language.

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.