JWT Decoder
Decode and validate JWT tokens instantly. View header, payload, and signature. Check expiration status. Free JWT decoder tool.
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What is JWT Decoder?
JWT Decoder is a tool that decodes JSON Web Tokens (JWT) to reveal their header, payload, and signature. JWTs are compact, URL-safe tokens used for authentication and information exchange in web applications, APIs, and single sign-on systems.
Key Benefits
- Instant decoding
- Shows all token parts
- Expiration checking
- No server required
Common Use Cases
- •API debugging
- •Authentication troubleshooting
- •Token validation
- •Security auditing
How to Decode JWT Tokens
- Paste your JWT token: Copy the complete JWT token (the long string starting with "eyJ...") and paste it into the input field.
- View the decoded parts: The decoder instantly shows three sections: Header (algorithm info), Payload (claims data), and Signature (verification).
- Check token validity: Look for the expiration (exp) claim to see if the token is still valid. Expired tokens will be marked with a warning.
- Copy decoded JSON: Click to copy the header or payload as formatted JSON for use in documentation or debugging.
Key Features
- Decode JWT header, payload, and signature
- Expiration time validation
- Formatted JSON output
- Copy decoded data as JSON
- Identifies signing algorithm
- Client-side only - tokens never transmitted