NEW: JWT Validator

Visit 👉 https://jwtvalidator.dev

What This Tool Does

• Decodes the header and payload of any signed JWT and displays them with syntax highlighting
• Warns when a token uses alg: none, which has no signature and should never be trusted in production
• Inspects standard claims (exp, nbf, iat) and shows timestamps and validity status
• Displays all claims in the payload (both standard and custom) in a human-readable format
• Optionally verifies the cryptographic signature using a public key or shared secret via the native Web Crypto API
• Auto-detects whether a pasted key is JWK or PEM format
• Auto-detects UTF-8 vs Base64 encoding for HMAC secrets

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JWE Not Supported

This tool validates signed JWTs (JWS) with 3 parts. Encrypted JWTs (JWE) are not supported.

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Client-Side Only

This validator runs entirely in the browser. No JWTs are transmitted, stored, or logged on any server.