JWT Decoder
Inspect a JWT's header and payload.
100% in your browser — nothing uploadedAbout this tool
Decode a JSON Web Token to read its header and payload, with human-readable timestamps. Decoded locally — your token is never uploaded and the signature is not verified.
- Files are processed on your device — nothing is uploaded.
- No account, no watermark, no daily limits.
- Works offline once the page has loaded.
Frequently asked questions
- Is my token sent anywhere?
- No. The JWT is decoded entirely in your browser — important, since tokens are sensitive credentials.
- Does it verify the signature?
- No. Decoding only reads the header and payload; verifying the signature requires the secret or public key, which this tool never asks for.
- What are exp / iat / nbf?
- Standard JWT time claims (expiry, issued-at, not-before). They're shown as human-readable UTC times.