Harry Potter universe database with characters, spells, potions and more.
PotterDB API is a free Entertainment API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Documentation for Potter DB
Details from docs.potterdb.com.

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Get useless, but true facts
The PotterDB API is provided by Potter DB: Docs (docs.potterdb.com). Documentation for Potter DB
Yes. The PotterDB API is listed in the Entertainment 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 PotterDB API requires no authentication, so you can start making requests without signing up.
Yes. The PotterDB API supports CORS, so front-end JavaScript can call it directly.
Yes. The PotterDB API is served over HTTPS, so it's safe to use in production.