Crypto

JWT Decoder

Decode JWT header and payload locally, with optional HMAC signature verification.

JWT

Output

Explanation

Decodes the header and payload and shows algorithm, expiry, and verification status. The signature is only checked when you provide an HMAC secret (HS256/384/512). Decoding is not verification — never trust unverified claims.

Security Notice

All processing happens locally in your browser whenever possible. Your data is not uploaded unless explicitly stated.