JWT Generator
Build and sign JSON Web Tokens (HS256/384/512) in your browser
Build a JSON Web Token and sign it with an HMAC secret right in your browser. Provide a payload of claims, pick HS256, HS384, or HS512, and the tool assembles the header, base64url-encodes both segments, and signs them with the Web Crypto API. It pairs with the JWT Debugger, which can decode and verify the tokens you produce here.
How to use JWT Generator
- Enter your claims as a JSON payload.
- Choose the HMAC algorithm (HS256, HS384, or HS512).
- Enter the signing secret.
- Click generate to produce the signed token, then copy it.
Frequently asked questions
Which algorithms are supported?
The HMAC family — HS256, HS384, and HS512 — signed with the Web Crypto API. Asymmetric algorithms such as RS256 need a private key and are not generated here.
Does my secret leave my device?
No. The payload and secret are used only in your browser, via the Web Crypto API, to compute the signature; nothing is sent to a server.
Should I use this for production tokens?
Treat it as a development and debugging aid. For real tokens, sign on a trusted server and never expose production signing secrets in a browser.
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