About JWT Generator
Build and sign a JSON Web Token (JWT) for testing. Set the header and payload claims and a secret to produce a signed HS256 token you can use in local development.
How to Use
- Edit the header and payload claims.
- Enter a signing secret.
- Generate the signed JWT.
- Copy it for use in your test requests.
Why Use This Tool?
- Accurate — built on precise, well-tested mathematical formulas.
- Instant — all calculations happen client-side for zero latency.
- Private — no data is sent to any server; your information stays on your device.
- Free — no sign-up, no limits, no hidden costs.
Frequently Asked Questions
Is it safe to enter a real secret here?
Use only throwaway/test secrets. While signing happens in your browser, you should never paste production signing keys into any web tool.
What is the difference between the decoder and the generator?
The decoder reads an existing token's contents; the generator builds a new signed token from claims you provide. Use the generator to create test tokens and the decoder to inspect them.
Which algorithm does it use?
It produces HS256 (HMAC-SHA256) tokens, the most common symmetric JWT algorithm, where the same secret signs and verifies the token.