Create a signed HS256 JWT
A JSON Web Token carries claims — like who a user is and when their session expires — signed so the server can trust it hasn't been tampered with. This tool builds a token from the claims you provide and signs it with HS256 using a secret you supply, which is useful for testing an endpoint or understanding how tokens are assembled. It all runs in your browser.
How to use it
- Enter the payload claims you want to include.
- Provide a signing secret.
- Generate the token and copy it for testing.
Typical claims
sub— the subject, usually a user identifier.exp— an expiry time, so the token can't be used forever.iss— who issued the token.
Questions people ask
Is this safe for production tokens? Generate real tokens on your server where the secret is protected. Use this for testing and learning, with a throwaway secret.
Does my secret leave the browser? No — signing happens locally, but still avoid pasting a live production secret.