JWT Decoder
Decode and inspect JWT tokens — header, payload, and expiration
How to Use JWT Decoder
Decode and inspect JSON Web Tokens to view their header, payload, and expiration status. Invaluable for debugging authentication flows.
- 1
Paste your JWT
Paste the full JWT string (header.payload.signature) into the input field.
- 2
View decoded parts
The tool splits the token into its three color-coded parts and shows the decoded header and payload as formatted JSON.
- 3
Check expiration
If the token contains an exp claim, the tool automatically shows whether it's expired and the exact expiration time.
Frequently Asked Questions
What is a JWT token?
JWT (JSON Web Token) is a compact, URL-safe token format used for securely transmitting information between parties, commonly used for authentication.
Can I verify JWT signatures?
This tool decodes and displays JWT contents. Signature verification requires the secret key and is not supported in the browser for security reasons.
Is it safe to paste my JWT here?
Yes, all decoding happens in your browser. No tokens are sent to any server.
How do I check if a JWT is expired?
The tool automatically detects the exp claim and shows whether the token is expired with a human-readable expiration time.
Is this tool free?
Yes, completely free with no signup required.