Online Sudoku - Sudokumax
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Trivia Questions.
Open Trivia API is a free Games & Comics API that requires no API key, is served over HTTPS and has unconfirmed CORS support.
Free to use, user-contributed trivia questions!
Details from opentdb.com.

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Monster Hunter World data
Mojang / Minecraft API
Yes. The Open Trivia API is listed in the Games & Comics category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The Open Trivia API requires no authentication, so you can start making requests without signing up.
CORS support for the Open Trivia API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Open Trivia API is served over HTTPS, so it's safe to use in production.