JWT Decoder
Runs locally
Paste a JSON Web Token to view its decoded header and payload. This tool decodes JWT contents — it does not verify the token signature.
- Free to use
- No registration
- Runs locally in your browser
- Your data is never uploaded
This tool decodes JWT contents. It does not verify the token signature.
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Header
Your data is processed locally in your browser and is not uploaded.
Learn more about this tool⌄
Example
A sample HS256 token (jwt.io's own example token)
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c
Header: {"alg":"HS256","typ":"JWT"}\nPayload: {"sub":"1234567890","name":"John Doe","iat":1516239022}How it works
The token is split on its three segments; the header and payload segments are Base64URL-decoded and parsed as JSON.
Common use cases
- Debugging authentication issues
- Inspecting claims during development
Frequently asked questions
- Does this verify the signature?
- No. It only decodes the header and payload. Signature verification is intentionally not performed.
- Is my token sent anywhere?
- No. JWTs may contain sensitive data, so decoding happens only in memory in your browser.