JWT Builder
Build a JWT — set headers, claims, and sign with HS256/384/512 entirely in your browser.
Quick claims:
JWT
🔒 Signing uses SubtleCrypto in your browser. Secrets never leave your machine.
About this tool
Builds and signs JWTs in your browser. Symmetric algorithms only —HS256, HS384, HS512 — plus none for unsigned tokens (testing only — never accept alg: none in production).
For RS/ES signing you need a private key; that's a different beast and out of scope here. To inspect an existing JWT, see the JWT Decoder.
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