DeveloperToolsKitBETA

JWT Decoder & Verifier

Analyze JWT (JSON Web Token) tokens, view their content and check their validity.

Signature Algorithm

Header

Header contains the token type and the hash algorithm used.

Payload

Payload contains the actual data within the token. User information and validity period data are found here.

Signature

Signature is used to verify that the token has not been tampered with. Header and payload are signed using a secret key.

Note: Signature verification requires a secret key on the server side. This tool only parses the token.

JWT Decoder & Token Analyzer

Decode, analyze, and validate JSON Web Tokens (JWT) with detailed header and payload inspection. Essential for debugging authentication systems and API security.

Token Decoding

Decode JWT tokens to reveal header, payload, and signature components with syntax highlighting.

Security Analysis

Analyze token expiration, algorithm compatibility, and security best practices validation.

Time Validation

Check token validity periods with issued at (iat), expires at (exp), and not before (nbf) claims.

Authentication Applications

  • API Authentication

    Debug JWT tokens used in REST API and GraphQL authentication flows

  • OAuth & SSO Systems

    Analyze tokens from OAuth providers and Single Sign-On implementations

  • Microservices Security

    Validate service-to-service authentication tokens in distributed systems

  • Mobile App Integration

    Debug authentication tokens in mobile applications and native apps

JWT Structure & Algorithms

Symmetric Algorithms
HS256, HS384, HS512
HMAC with SHA-256/384/512
Asymmetric Algorithms
RS256, RS384, RS512, ES256, ES384, ES512
RSA and ECDSA signatures
Token Structure
header.payload.signature
Base64URL encoded components

🔐 JWT Security Best Practices

• Use strong signing algorithms

Prefer RS256 over HS256 for production systems

• Set appropriate expiration times

Short-lived tokens reduce security risks

• Validate all token claims

Check iss, aud, exp, and custom claims

• Never store sensitive data in payload

JWT payload is only encoded, not encrypted

💾Bookmark this tool for later use
• Press Ctrl+D (Cmd+D on Mac)