Generate signed JWTs with custom payloads using HS256/HS384/HS512. Decode any JWT token and inspect header, payload, and signature — runs in your browser.
The JWT Generator creates signed JSON Web Tokens using the browser's built-in Web Crypto API. Choose an algorithm, enter your secret, configure payload claims, and get a production-ready signed token instantly.
Supports HMAC algorithms: HS256, HS384, and HS512. Add any custom claims with string, number, or boolean types. Standard claims like iat and expare pre-filled automatically.
Paste any JWT to instantly decode its header and payload. The tool performs base64url decoding without making network requests. Signature verification is not performed in the decoder tab — use the Generator tab with a known secret for that purpose.
All cryptographic operations use the browser's SubtleCrypto API. Your secret key and token never leave your device.