JWT Decoder – Decode and Inspect JWT Tokens in Browser
The JWT decoder parses JSON Web Tokens and displays header, payload, and signature sections clearly. Works entirely in browser — token never leaves your computer.
Paste JWT token into the field and immediately see token contents: user data, expiration time (exp), issuer (iss), and other claim fields. Useful for developers debugging API integrations.
What is a JWT token and how does it work?
JWT (JSON Web Token) is a compact way to securely transmit information between parties. It consists of three Base64-encoded parts separated by dots: header (algorithm), payload (data/claims), and signature. The payload is readable without encryption keys ��� never store passwords or sensitive data in JWT as it's only encoded, not encrypted.
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Browse all tools →JWT decoder breaks down JSON Web Token strings into readable parts without requiring encryption keys. A handy tool for developers checking token content and validity.
Enter a JWT string and the tool displays its header, payload, and signature parts in readable format.
- Break down JWT header and payload into readable JSON objects.
- Check token expiration time (exp), issuer (iss), and other fields.
- Copy individual fields to clipboard for further use.
The decoder shows token content but doesn't verify signature correctness.
- The payload section is not encrypted – anyone can read it without a key.
- Signature verification requires the secret key, which this tool doesn't use.
- Time fields (exp, iat, nbf) values are Unix timestamps – the tool converts them to readable format.
JWTs often contain sensitive information – handle tokens carefully.
- Don't share production environment tokens with public services.
- Decoding happens entirely in the browser – no data is sent to servers.
- Expired or forged tokens won't pass server-side verification.