About This Tool
Documentation
What does this tool do?
A comprehensive JWT inspection suite. Decodes header and payload claims (iss, sub, aud, exp, nbf, iat), displays live expiration countdown timers, highlights active vs expired status, and provides optional cryptographic signature verification (HS256, HS384, HS512) using shared secret keys.
When should you use it?
Use this tool to debug authentication issues in OAuth 2.0 / OpenID Connect workflows, verify user permissions and roles inside tokens, inspect token expiration timestamps, or audit JWT security.
Key Capabilities & Features
Highlights
Decode JSON Web Tokens (JWT) into Header, Payload, and Signature components instantly
Human-readable expiration (exp), issued at (iat), and not before (nbf) timestamp parsing
Algorithm detection supporting HS256, HS384, HS512, RS256, ES256, and EdDSA
Signature verification sandbox with custom HMAC secret or public RSA key input
Client-side token parsing guaranteeing sensitive secrets never leave your device