01
Runs entirely in your browser
JWT Decoder
Inspect JWT headers and payloads instantly. Nothing is uploaded or sent to a server.
Token
Paste a JWT or a Bearer token.
Your decoded token will appear here
Header and payload fields will be separated for quick inspection.
Decoded locally
Token details
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Payload
03
Signature
A decoder can read a JWT, but decoding does not verify its signature or prove the token is trustworthy.
QUICK GUIDE
How to use the JWT Decoder
01
Paste your JWT into the token field.
02
Decode it to parse the header and payload.
03
Inspect claims and copy or download the result.
Common questions
Can this tool verify a JWT signature?
No. It only decodes the header and payload. Signature verification requires the appropriate cryptographic algorithm and key.
Does decoding reveal the JWT secret?
No. JWT header and payload data are encoded, not encrypted. The signing secret is not contained in those sections.
Is my token sent anywhere?
No. The decoder is implemented entirely in client-side JavaScript, so the token remains in your browser.
What if my token is invalid?
The tool checks the three-part structure, Base64URL encoding, UTF-8 decoding, and JSON structure, then explains what failed.