JWT Decoder

Decode and inspect JWT tokens for development

Security Note

This tool only decodes and displays JWT contents. It does NOT verify signatures or validate tokens. Never share sensitive tokens publicly.

How to Decode JWT Tokens

  1. Paste JWT token
  2. View decoded header and payload
  3. Inspect claims and metadata
  4. Note: Signature verification not performed

JWT Decoder Features

  • Decode Header: View algorithm and token type
  • Decode Payload: Inspect claims, expiration, issuer
  • No Verification: Decoding only, no signature validation
  • Formatted JSON: Pretty-printed output for readability
  • Developer-Friendly: Quick debugging of JWT structure
  • 100% Free: No limits on decoding

What are JWT Tokens?

JWT (JSON Web Token) is a compact URL-safe token format for transmitting claims between parties. Structure: header.payload.signature (three Base64URL-encoded parts separated by dots). Header contains algorithm (HS256, RS256), payload contains claims (sub, exp, iat), signature verifies integrity.

Example JWT: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c. This tool decodes header and payload but does NOT verify the signature—use this for debugging, not for security validation.

Use cases: Debugging authentication issues, inspecting token expiration times, checking claims in API responses, understanding JWT structure during development, verifying token contents without backend access, and troubleshooting SSO integration. Always verify JWTs on the server for security.

Privacy & Security

All JWT decoding happens locally in your browser. Your tokens are never uploaded to servers, stored, or logged. The decoding uses JavaScript, keeping your tokens completely private. Remember: JWTs are not encrypted, only signed—don't store sensitive data in payloads.