JWT decoder
Inspect the header, payload and signature of a JSON Web Token. Decoding only — no secret leaves your browser.
Active · exp 10/20/2030, 6:46:40 PM
Header
{
"alg": "HS256",
"typ": "JWT"
}Payload
{
"sub": "user_8421",
"name": "Avery Carter",
"role": "admin",
"iat": 1718745200,
"exp": 1918748800
}Signature
3v8Nq2bQ1xs5pXqg9mJb7kZC0rFt8wYpL2nQ4dRkXyA
Inspect the header, payload, and signature of a JSON Web Token. Decoding only — no secret leaves your browser.
Frequently asked questions
- What is a JWT?
- A JSON Web Token (JWT) is a compact, URL-safe token format defined in RFC 7519. It contains a Base64URL-encoded header, payload, and signature separated by dots.
- Can this tool verify a JWT signature?
- No. This tool only decodes the header and payload. Signature verification requires the secret key and must happen server-side.
- What does the exp claim mean?
- The exp (expiration time) claim is a Unix timestamp indicating when the token expires. This tool shows whether the token is currently expired.