Crypto

Webhook Signature Validator

Verify Stripe and GitHub webhook signatures. HMAC-SHA256. 100% client-side — your secret never leaves the browser.

Exact UTF-8 body as received — no JSON parsing or reformatting.

100% client-side — Web Crypto API. Secret never leaves your browser.

How to use

  1. Enter a domain, URL, or value relevant to Webhook Signature Validator.
  2. Run the check and review the output carefully.
  3. Apply recommended fixes, then run the check again to verify.

Common use cases

  • Pre-deployment validation for Webhook Signature Validator.
  • Incident triage when security checks fail in production.
  • Periodic security review as part of technical SEO and hardening.

Common issues and fixes

Body modification

Express/Next.js may parse JSON and change the body. Use raw body for verification.

Wrong secret

Stripe: use whsec_ from Dashboard or Stripe CLI. GitHub: use webhook secret from repo settings.

Recommended remediation

Stripe: t=timestamp,v1=sig. GitHub: sha256=hex. Both need exact raw UTF-8 body — no parsing.

FAQ

Is Webhook Signature Validator free to use?

Yes. This tool is free and can be used without account registration.

Do you store submitted values?

Only the minimum processing needed for the check. For client-side tools, data stays in your browser.

How should I use these results?

Use the output as a diagnostic baseline, apply fixes in your stack, then re-run the check to confirm remediation.

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