JWT Decoder
Decode and inspect JSON Web Tokens. View header, payload, and signature details.
Fonctionnalites
[AUTO_TRANSLATED:fr] Instant Decode
[AUTO_TRANSLATED:fr] Decode JWT tokens instantly in your browser
[AUTO_TRANSLATED:fr] Expiry Check
[AUTO_TRANSLATED:fr] Automatically detect if the token has expired
[AUTO_TRANSLATED:fr] 100% Private
[AUTO_TRANSLATED:fr] All processing happens locally, no data sent to servers
[AUTO_TRANSLATED:fr] One-Click Copy
[AUTO_TRANSLATED:fr] Copy header, payload, or signature with one click
Understanding JWT Structure
Header
Contains metadata about the token including the signing algorithm (alg) and token type (typ). Common algorithms include HS256, RS256, and ES256.
Payload
Contains the claims - statements about the user and additional data. Standard claims include iss (issuer), sub (subject), exp (expiration), iat (issued at), and aud (audience).
Signature
Created by signing the encoded header and payload with a secret key. Used to verify the token hasn't been tampered with. Note: This tool decodes but does not verify signatures.
Comment utiliser
- Paste your JWT token in the input field
- Click "Decode" or press Enter to decode the token
- View the decoded header, payload, and signature
- Check expiration status and other claims
- Copy any section to your clipboard
FAQ
What is a JWT (JSON Web Token)?
JWT is a compact, URL-safe way to represent claims between two parties. It's commonly used for authentication and information exchange in web applications.
Is my token secure when using this tool?
Yes, all decoding happens locally in your browser. Your token is never sent to any server. However, never share your tokens publicly as they may contain sensitive information.
Does this tool verify JWT signatures?
No, this tool only decodes the token to display its contents. Signature verification requires the secret key or public key, which should be done server-side.