Webhook Signature Tester

Compute, verify, and debug HMAC webhook signatures for Stripe, GitHub, Shopify, and more.

Payload & Secret

Warning: Extra whitespace/newlines in JSON strings change the signature. Paste the exact raw body.

Signature Configuration

Verify Existing Signature

Paste the signature header received in the webhook to verify it against your payload.

Computed Signature

Waiting for input...
Ready to verify

String to Sign

This is the exact string passed to the HMAC function.

Waiting for input...

Code Snippets (Node.js)