Decode and inspect JWT tokens online for free. View header, payload, and signature instantly. Useful for developers debugging authentication tokens.
Everything you need to know about using our JWT Decoder
JSON Web Token (JWT) is a secure way to transmit information between parties. Used for authentication (login sessions) and data exchange. Contains three parts: Header (algorithm), Payload (user data), and Signature (verification).
Paste the complete JWT string (eyJhbGciOiJIUzI1NiIs...). The decoder splits it into Header, Payload, and Signature sections. View the decoded JSON data, expiration time, and verify the signature algorithm instantly.
The decoder shows the signature algorithm (HS256, RS256, etc.) but cannot verify without the secret key. Use our signature verification tool if you have the secret/public key. This tool is for debugging and inspection.
Common fields: sub (user ID), iss (issuer), aud (audience), exp (expiration), iat (issued at), name, email, roles/permissions. View all claims in readable JSON format. Useful for debugging API tokens.
Decoding is safe - it only reads the token contents (which are Base64 encoded, not encrypted). However, never paste JWTs containing sensitive production data into any online tool. Use for development/testing tokens only.
Decode and inspect JWT tokens online for free. Our JWT decoder splits tokens into header, payload, and signature sections with formatted JSON display. Perfect for developers debugging authentication flows, security engineers validating token claims, and DevOps teams troubleshooting API gateway configurations. Supports RS256, HS256, ES256, and all standard JWT algorithms.
Paste your JWT token into the input field. The decoder automatically splits the token into three Base64-encoded parts: header (algorithm and type), payload (claims and user data), and signature (verification hash). Each section is decoded and displayed as readable JSON. View token expiration, issuer, audience, and custom claims. Verify signature format. All processing is local - tokens never leave your browser.
API debugging - inspect OAuth and OpenID Connect tokens during authentication flows
Security audit - verify JWT claims match expected roles, permissions, and expiration
Token validation - check token structure and signature before implementing in production
Microservices - debug service-to-service JWT bearer tokens in distributed architectures
Learning - understand JWT structure and claims for OAuth 2.0 and OIDC education
| Feature | Keynou | JWT.io | Token.dev |
|---|---|---|---|
| Price | Free | Free | Free |
| No Account | Yes | Yes | No |
| Algorithm Support | All | All | Limited |
| JSON Export | Yes | No | No |
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Decode and inspect JWT tokens online for free. View header, payload, and signature instantly. Useful for developers debugging authentication tokens.
All decoding happens in your browser. Your tokens never leave your device.
Real-time Base64 decoding with syntax highlighting and formatted JSON output.
Automatic detection of expiration dates and token validity status.