Free JWT Decoder Online
Decode JWT header and payload — no signature verification
Features
- Decodes header and payload
- Syntax-highlighted JSON output
- Clear warning that signatures aren't verified
- Runs entirely in your browser
Frequently Asked Questions
No — this only decodes the header and payload. It does not check the signature, so a token decoding cleanly does not mean it's authentic.
To inspect its claims while debugging — checking the expiration time, user ID, or custom fields an API or auth system embedded in the token.
No — decoding happens entirely in your browser. Since a JWT can contain sensitive claims, that matters for tokens you're actively debugging.
The header describes the token type and signing algorithm, the payload holds the actual claims (data), and the signature verifies the token wasn't tampered with — this tool decodes the first two but doesn't check the third.
Any standard JWT can be decoded here — the format is a public standard, not specific to any one service or provider.
How to Use JWT Decoder
Using JWT Decoder is simple and free. No sign-up required.
- Paste your JWT.
- Header and payload decode automatically.
- Read the decoded JSON on each side.
About JWT Decoder
JWT Decoder decodes the header and payload of a JSON Web Token directly in your browser, displayed as syntax-highlighted, readable JSON instead of the raw encoded string. This is useful for developers debugging authentication issues or inspecting what claims a token actually contains. It's important to note this tool decodes but does not verify the signature — a token decoding cleanly says nothing about whether it's authentic or was issued by a trusted source.
All iLoveToolZone tools work directly in your browser — no software installation or account required.