Useful Hacks

JWT Generator

Create and sign a JWT with an HMAC secret.

Signed locally in your browser using the Web Crypto API. Your secret is never sent anywhere.

Overview

Builds and signs a JSON Web Token using HMAC-SHA256 (HS256) — useful for generating test tokens during development.

How to use it

  1. 1Enter a payload as JSON.
  2. 2Enter the HMAC secret your server will verify against.
  3. 3The signed token updates automatically.

How it works

Base64url-encodes the header and payload, then signs the result with HMAC-SHA256 using the Web Crypto API — the same algorithm most JWT libraries use for HS256.

Tips

  • Only use this for test/development tokens with test secrets — never paste a real production signing secret into any web tool, including this one.

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