JWT Decoder
Inspect the header and payload of a JSON Web Token.
A JSON Web Token is three Base64URL-encoded parts — header, payload and signature — separated by dots.
About JWT Decoder
Paste any JSON Web Token to instantly decode and inspect its header, payload claims, and expiration, formatted as readable JSON. This JWT decoder is a go-to tool for debugging authentication flows and verifying token contents — decoding happens entirely client-side, so tokens are never transmitted or logged.
A JSON Web Token is three Base64URL-encoded parts — header, payload and signature — separated by dots. This JWT decoder splits the token, decodes the header and payload into readable JSON, and shows claims like issuer, subject and expiry so you can debug authentication problems quickly. Decoding never sends your token anywhere; it all happens in your browser.
How to use JWT Decoder
- Copy a JWT from your app, browser storage or an API response.
- Paste it into the token field.
- Read the decoded header and payload, including the exp, iat and sub claims.
- Check whether the token has expired before troubleshooting further.
Key features
- Instant decoding of header and payload into formatted JSON.
- Human-readable expiry and issued-at times.
- Runs fully client-side, so tokens are never logged or stored.
- Clear error if the token isn't a valid three-part JWT.
Common use cases
- Finding out why an API returns 401 by checking whether the token has expired.
- Confirming which scopes, roles or audience a token carries.
- Inspecting tokens from identity providers while building a login integration.