JWT Decoder
Decode JWT tokens and inspect their header and payload safely in your browser. No upload, no signature verification.
Decode a JWT token to inspect its contents.
How to use this tool
What this tool does and how it can help.
A JSON Web Token (JWT) is a compact, URL-safe token format used to transmit claims between systems. A JWT is typically split into three parts: header, payload, and signature.
The header identifies the token type and signing algorithm, the payload contains claims such as who the token belongs to and expiration metadata, and the signature is for integrity at the producer/consumer level.
This tool only decodes those parts in your browser so you can inspect the data quickly. Decoding does not mean verification. A token can be decodable but invalid, expired, or tampered with.
Common development use cases include API debugging, checking claim values during integration tests, and validating token structure during authentication flow troubleshooting.
FAQ
- Is my token uploaded anywhere?
- No. Everything is processed locally in your browser.
- Does this tool verify the JWT signature?
- No. This tool only decodes the token and does not verify its signature.
- Can I inspect the payload claims?
- Yes. The payload is decoded and displayed as formatted JSON.