JWT Decoder
Decode JSON Web Tokens instantly. View header, payload, and expiration status.
Frequently Asked Questions
What is a JWT token? +
A JSON Web Token (JWT) is a compact, URL-safe way to represent claims between two parties. It consists of three Base64-encoded parts separated by dots: a header (algorithm and type), a payload (claims/data), and a signature.
Does this tool verify JWT signatures? +
No. This tool only decodes and displays the header and payload. Signature verification requires the secret key or public key, which should never be shared with a client-side tool. Use a backend service for signature verification.
Is it safe to paste my JWT here? +
Yes. Everything runs entirely in your browser. The token is never sent to any server. However, be mindful that JWTs often contain sensitive information, so avoid sharing them in screenshots or public channels.
What do the colors in the decoded token mean? +
The three parts of a JWT are color-coded: red for the header, purple for the payload, and teal for the signature. This matches the standard JWT visualization convention and helps you identify each section.
How does the expiration check work? +
The decoder reads the 'exp' (expiration) claim from the payload, which is a Unix timestamp. It compares that to your current system time to determine if the token is expired, and shows a countdown or time-since-expiry.