Developer tools / Security

JWT Decoder

Read a JSON Web Token's header, payload, timestamps, and signature section without uploading it anywhere.

Decoded locally in your browser

Encoded JWTToken decoded

Decoded token

Signature not verified

This tool only decodes the token. A readable JWT is not proof that its signature or claims are trustworthy.

Issued

Jul 25, 2025, 01:46:40 AM UTC

Expires

Jul 25, 2026, 01:46:40 AM UTC

Not expired

Header

{
  "alg": "HS256",
  "typ": "JWT"
}

Payload

{
  "sub": "1234567890",
  "name": "Ada Lovelace",
  "role": "developer",
  "iat": 1753408000,
  "exp": 1784944000
}

Signature

demo-signature

Readable claims

Pretty-print header and payload JSON and turn Unix time claims into readable dates.

Expiration at a glance

Immediately see whether a token is expired, active, or has no expiration claim.

Safe expectations

Decoding is clearly separated from signature verification so readable data is never presented as trusted.

What this JWT decoder does

JWTs contain Base64URL-encoded sections that can be read without a secret key. This tool decodes those sections for debugging. It does not verify the cryptographic signature, issuer, audience, or any other security property. Always validate tokens in your application.