JWT Decoder
Decode a JSON Web Token to read its header and payload without any server round trip. A JWT is three Base64url segments separated by dots: a header describing the algorithm, a payload of claims and a signature. This decoder splits the token, Base64url-decodes the first two parts and pretty-prints them as JSON so you can inspect the issuer, subject, scopes and expiry while debugging auth. It also translates the exp and iat timestamps into readable dates so you can see at a glance whether a token is expired. Note that this tool does not verify the signature, since that requires the secret or public key; it is a decoder for inspection. Everything runs locally, so your tokens never leave the browser.
How to use JWT Decoder
- Paste your JWT into the input.
- Read the decoded header and payload.
- Check the expiry and claims.
Frequently asked questions
What parts of the JWT does it show?
It splits the token on its two dots and Base64url-decodes the header and payload so you can read the algorithm, claims and any custom fields.
Does it verify the signature?
No. It only decodes the token to inspect its contents. Decoding does not check whether the signature is valid, so do not trust an unverified token.
How are expiry claims shown?
Time claims like exp and iat are converted from Unix timestamps into human-readable dates so you can see when a token expires.
What is JWT Decoder?
Decode a JSON Web Token to read its header and payload without any server round trip. A JWT is three Base64url segments separated by dots: a header describing the algorithm, a payload of claims and a signature.
Is JWT Decoder free to use?
Yes. JWT Decoder is completely free, with no sign-up and no usage limits.
Does JWT Decoder work in a web browser?
Yes. JWT Decoder runs in any modern web browser. There is nothing to download or install.
Is my data private with JWT Decoder?
Yes. JWT Decoder runs entirely on your device in your browser, so nothing you enter is uploaded to a server.
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