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Welcome to Merriam-Webster's Developer Center!

The Merriam-Webster Dictionary API gives developers access to a comprehensive resource of dictionary and thesaurus content as well as specialized medical, Spanish, ESL, and student-friendly vocabulary. Make your applications better by integrating our authoritative definitions, etymologies, audio pronunciations, synonyms and antonyms, and more. Our robust API empowers developers to enhance word games and create educational, language learning, and other word-related applications for the digital environment. We look forward to seeing all of the new, innovative products powered by Merriam-Webster's trusted references.

Free API

The Merriam-Webster Dictionary API is free as long as it is for non-commercial use, usage does not exceed 1000 queries per day per API key, and use is limited to two reference APIs.

Commercial Use

If your app is for commercial use (either monetized via ads or a paid fee), please contact us directly so we can approve use and develop business terms on a case-by-case basis.

Get Started Using Our API

  • Visit our Products pages and decide which reference APIs you would like to use.
  • Register your application with us. You will request your API Key(s) when you register.
  • Once registered, you will receive a verification e-mail. Click on the link in the verification email to complete your registration.
  • Sign in to dictionaryapi.com and visit the My Keys page to retrieve your API Key(s).
  • You may now begin using our API in your app!
  • You will need to call our API using the "API Request URL" provided on each reference's Product page. This URL must include your API Key, which is specific to your application.