DevTools / Encoders
JWT Decoder
Paste a JSON Web Token to instantly view its header and payload claims — decoded entirely in your browser.
Runs entirely in your browser · No data uploaded
What is JWT Decoder?
A JWT (JSON Web Token) is a compact, URL-safe token format used for authentication and authorization. It consists of three Base64URL-encoded parts separated by dots: a header (algorithm info), a payload (claims/data), and a signature. This tool decodes the header and payload so you can inspect their contents — it does not verify the signature.
FAQ
Does this verify the JWT signature?
No — this tool only decodes and displays the header and payload. It doesn't check the signature against a secret or public key, since that would require you to share sensitive key material.
Is my token sent anywhere?
No. Decoding happens entirely in your browser using JavaScript — your token never leaves your device.
Why does my token show 'Invalid JWT'?
A valid JWT has exactly three parts separated by dots (header.payload.signature). Check that you've pasted the complete token without extra whitespace or line breaks.