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7/1/2026
I built a browser-only JWT Creator & Signer — HS256/384/512, verify, expiry check, 77 tests

I built a browser-only JWT Creator & Signer — HS256/384/512, verify, expiry check, 77 tests

Short summary

A developer built a free, browser-only JWT creator and signer using Web Crypto API—sign tokens with HS256/384/512, verify signature and expiry, generate secrets entirely client-side. The tool includes 77 tests covering base64url encoding, HMAC algorithm mapping, and error states. Because all operations run locally via Web Crypto API, signing secrets never leave your machine.

  • •Browser-only JWT creator/signer with HS256/384/512 HMAC support and expiry verification
  • •77 tests cover encoding edge cases, algorithm mapping, and error handling
  • •Client-side only—your signing secrets never leave your browser

Generated with AI, which can make mistakes.

#product-launch#open-source
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