Show HN: JWT Lens – decode and verify JWTs offline, provably no network

Category: security

Tags: jwt, security, offline-tool

Score: 6.0/10 (Innovation: 6, Technical: 5, Documentation: 7, Utility: 6)

JWT Lens is a single HTML file that decodes and verifies JSON Web Tokens entirely offline with no network dependency, leveraging a strict CSP and browser WebCrypto for trust and security. Its unique approach of provable offline operation and built-in self-test makes it a neat tool for developers who need to inspect JWTs privately. It addresses a real trust gap in online decoders while keeping the code small and auditable.

Target audience: backend devs, security engineers

Repository: https://github.com/milovance23/jwt-lens · HTML · Unlicense

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