JWT Decoder
Decode and analyze JWT tokens with header, payload, and signature display. Check expiration status and validate structure. 100% private - all processing happens in your browser.
Complete Decoding
Decode all three parts of JWT: header, payload, and signature with formatted JSON output.
Validation
Automatically validate JWT structure and check expiration status based on exp claim.
100% Private
All decoding happens in your browser. Your JWT token never leaves your device.
Frequently Asked Questions
What is a JWT token?
JWT (JSON Web Token) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed.
What are the three parts of a JWT?
A JWT consists of three parts separated by dots (.): Header (contains token type and signing algorithm), Payload (contains claims/data), and Signature (ensures the token hasn't been tampered with).
How do I decode a JWT token?
Simply paste your JWT token in the input area. The tool will automatically decode and display the header, payload, and signature. It will also check if the token is expired and validate its structure.
Does this tool verify JWT signatures?
No, this tool only decodes and displays JWT structure. It does not perform cryptographic signature verification, which requires the secret key. It does validate the JWT structure and check expiration status.
What is the exp claim in JWT?
The exp (expiration time) claim identifies the expiration time on or after which the JWT must not be accepted for processing. The value is a NumericDate value (seconds since Unix epoch).
Is my JWT token safe when using this tool?
Yes, absolutely! All decoding happens in your browser. Your JWT token never leaves your device and is not sent to any server, ensuring complete privacy and security.