JWT Signer
Create and sign JSON Web Tokens with HMAC algorithms using the Web Crypto API.
About this tool
Create and sign JSON Web Tokens with HMAC, RSA, or ECDSA algorithms using the Web Crypto API. JWT Signer runs in the browser on DevTools. There is no signup, and your input stays on this device unless the tool explicitly performs a live network lookup.
What this tool does not do
- JWT Signer is a free in-browser utility, not a hosted API. It does not keep server-side history and is not a substitute for production verification in your own stack.
How do I use this tool?
How do I use JWT Signer?
Open JWT Signer, enter or paste your input, and copy the result. The page works without an account.
Related guides
JWT Validator: Verify Signatures and Claims Online
Validate HS256 and RS256 JWT signatures plus exp, nbf, aud and iss claims — client-side, pairs with JWT Decoder. Confirm claims after you decode the token.
JSON Web Tokens (JWT) Explained: A Complete Guide for Developers
What a JWT is, how the header.payload.signature structure works, which claims matter, and how to sign and verify tokens securely — with examples you can run in your browser.
How to Decode a JWT and Read Its Claims
A step-by-step guide to decoding a JSON Web Token by hand — Base64url decoding the header and payload, understanding common claims, and why decoding is not the same as verifying.
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