JWT Decoder: Inspect Token Header and Payload
Decode a JWT header and payload as readable JSON. Decoding does not verify the signature or prove that a token is trusted.
This guide and page information are in English. Some controls inside the interactive tool currently appear in Turkish.
This tool processes its main input in your browser and does not send it to an external API. Fonts and interface assets may load from external providers.
JWT Decoder: Inspect Token Header and Payload
The JWT decoder reads the header and payload portions of a JSON Web Token from their Base64URL representation. It can help inspect claims while debugging a local test flow.
Decoding does not verify a signature or establish authorization. Treat real access tokens as credentials: do not paste them into a public tool; use fake or revoked test values.
How to use it
- Enter only a fake or revoked test token.
- Review the decoded header and payload fields.
- Verify signature and claims inside your application using a trusted key and environment.
Example
Input: A three-part test JWT
Output: Header and payload are decoded; this view does not validate the signature.
Who is it for?
- Backend developers
- API engineers
- Students learning token formats
Privacy and limitations
Decoding runs in this browser and the tool does not send the token to an API. Still treat real tokens as secrets.
Frequently asked questions
Does this decoder verify a JWT signature?
No. It displays token parts. Your application must verify the signature, algorithm, issuer, audience and expiration before trusting claims.
Should I paste a production token?
No. A bearer token is a credential. Use fake or revoked test data instead.
Is a JWT payload private?
Most JWT payloads are Base64URL-encoded, not encrypted. Anyone with the token can decode that content.
Can it tell whether a token is expired?
You can read an `exp` claim, but the page does not verify the signature or whether a server will accept the token.