JWT Verifier
HS256 · RFC 7519Verify HS256 JWT signatures online. Paste a token and HMAC secret; this jwt verifier uses Web Crypto API for secure verification.
How to verify a JWT signature online
This tool operates as a versatile jwt verifier and verify jwt signature online. Paste your JWT token and the same HMAC secret that was used to sign it, then click Verify Signature. The tool recomputes the HMAC-SHA256 using your secret and checks whether it matches the signature embedded in the token - entirely inside your browser.
Why does signature verification matter with VERIFY JWT SIGNATURE ONLINE
A decoded JWT shows you the claims, but without verifying the signature you cannot trust them. Verification proves the token was signed by someone who holds the correct secret key and that the payload has not been modified in transit.
Frequently Asked Questions
What is required for a jwt verifier to check a signature?
The jwt verifier needs the raw JWT string and the cryptographic secret key to compute the HMAC-SHA256 signature and match it.