JWT Decoder

Why use JWT Decoder?

JWT Decoder runs locally using your browser's built-in cryptography, so passwords, keys and hashes are never uploaded or logged.

• Runs instantly in your browser — nothing to install, nothing uploaded.
• Completely free, with no account, no watermarks and no usage limits.
• Structure: header.payload.signature (Base64URL)
• Paste a JWT (three dot-separated segments) into the input.
• Works on any device — desktop, tablet and phone — and is fully keyboard accessible.

How to use JWT Decoder

1. Paste a JWT (three dot-separated segments) into the input.
2. The header and payload are decoded and pretty-printed automatically.
3. Review registered claims (iss, sub, aud, jti) and timing (iat, nbf, exp).
4. Copy the header, payload, or everything. The signature is shown as opaque text.

Examples

• Inspecting an access token's expiry to see whether it has lapsed.
• Reading the 'sub' and 'iss' claims of a demo token.

Supported formats

• Structure: header.payload.signature (Base64URL)

Limitations

• Decoding does NOT verify the signature — it cannot prove the token is authentic or untampered.
• It never contacts a server, loads URLs found in claims, or stores your token.
• Extremely large tokens are rejected to protect performance.