Code Tower · room 6
JWT Decoder
Decode JSON Web Token header and payload.
🔒 Processed in your browser · No upload · No sign-up
⚠️ The signature is not verified. Never trust a token's contents without server-side verification.
What is inside a JWT?
A JWT has three Base64URL-encoded parts separated by dots: a header (algorithm and type), a payload (claims such as sub, exp and iat) and a signature. This tool decodes the first two so you can debug authentication flows. Tokens are decoded locally and never sent anywhere.