What algorithms are supported?

HS256 (HMAC-SHA256), HS384 (HMAC-SHA384), and HS512 (HMAC-SHA512). All use the Web Crypto API for signing.

Is my secret key safe?

Yes. Everything runs locally in your browser. The secret key and generated token never leave your device.

This tool is great for development and testing. For production, use a server-side JWT library with proper key management.

Generate JSON Web Tokens entirely in your browser

Algorithm:

Header (JSON)

Base64URL: ewogICJhbGciOiAiSFMyNTYiLAogICJ0eXAiOiAiSldUIgp9

Payload (JSON)

Base64URL: ewogICJzdWIiOiAiMTIzNDU2Nzg5MCIsCiAgIm5hbWUiOiAiSm9obiBEb2UiLAogICJpYXQiOiAxNTE2MjM5MDIyCn0

Secret Key