JWT Decoder
Decode a JSON Web Token's header and payload without verifying it.
Header
Payload
How to use JWT Decoder
- 1Paste a JWT (three base64url segments separated by dots).
- 2The header and payload are decoded automatically.
- 3Copy either section as formatted JSON.
Why use this tool
- Runs fully client-side — your token, which may contain sensitive claims, never leaves your browser.
- Shows standard claims like exp and iat as human-readable dates.
- Clear error if the token is malformed.
Frequently asked questions
Does this verify the token's signature?
No. This tool only decodes the header and payload for inspection — it does not verify the signature, which requires the secret or public key.
Is it safe to paste a real production token here?
Decoding happens entirely in your browser and nothing is transmitted, but as a general rule avoid pasting production secrets into any web tool.