📜 JWT Decoder & Verifier
Decode a JSON Web Token (JWT) into Header & Payload and (optionally) verify its signature. Runs locally in your browser.
Tip: payload is not encrypted in JWT. Do not paste secrets into payloads. For signature check, use HS256 secret or RS256 public key.
Input token
Decoded
Header
Payload
Signature (raw, Base64url)
Verify signature
Algorithm will be detected from header (alg). Supported: HS256, RS256.
What is JWT?
JSON Web Token (JWT) is an open standard (RFC 7519) for securely transmitting claims between parties. It is commonly used for authentication in modern web apps.
How to use this JWT tool
- Paste your JWT to instantly decode the header and payload.
- View claims such as
exp,iat,nbfwith human-readable dates. - Verify signatures using HS256 secret or RS256 public key.