Webhook Signature Verifier
Verify Stripe, GitHub, Slack, and generic HMAC webhook signatures in the browser.
Sensitive data: Anything you enter is processed in your browser only. It is never uploaded or logged on a server.
Verifying webhook signatures
Providers like Stripe, GitHub, and Slack sign payloads with HMAC using shared secrets or asymmetric keys. Verifiers recompute digests on the raw request body exactly as received, before JSON parsing reorders bytes.
Signature headers often include timestamps to prevent replay; reject stale events per vendor tolerance. Constant-time comparison prevents timing side channels in custom middleware.
Use provider test vectors from documentation when first integrating. Rotate secrets if a signing key was pasted into a ticket during debugging.
Verify signatures locally with captured raw bodies from staging webhooks. Avoid uploading payloads containing customer PII to third-party signature checkers.
Reference Guide
Security tool - all processing runs locally in your browser. No data is sent to a server.
Operation: webhook-verify
Paste input, click Run, and copy the result. For two-input tools, fill both fields before running.
Example Input
Sample input for webhook-signature-verifier
A sample loads automatically when you open this tool. Use Load Sample to reset it.