HMAC Generator
Sign payloads with HMAC to test webhook verification.
IT Password Policy — Ready-to-Adopt Template
A NIST SP 800-63B aligned policy document you can rename, sign and hand to an auditor.
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About this tool
HMAC combines a secret key with a hash function to prove both integrity and authenticity. Stripe, GitHub and most webhook providers sign payloads this way, and this tool reproduces the digest locally so you can debug verification code.
Reproducing a webhook signature
Concatenate the exact raw body — not a re-serialised object — with any timestamp prefix the provider requires, then HMAC it with your signing secret.
Comparing signatures safely
Always compare with a timing-safe function on the server. A plain string equality check leaks timing information.
How to use HMAC Generator
- 1
Open HMAC Generator
Everything runs on this page — there is nothing to install and no account required to use the free features.
- 2
Add your input
Paste or enter your values in the panel above. The tool updates as you type, so you can iterate quickly.
- 3
Review the output
Check the result, copy it with one click, and adjust the options until it matches what your system expects.
- 4
Take it further
Use the security & infrastructure tips below to make the result production-ready, then unlock the gated extras via the form above.
Best practices
- Treat every result as a snapshot — configuration drifts, so re-check after each deploy.
- Fix the highest-impact finding first rather than chasing a perfect score.
- Apply changes at the shared layer (proxy, CDN, base image) so every service inherits them.
- Document what you changed and when; auditors and future teammates will ask.
Why HMAC Generator matters
Infrastructure and security misconfigurations are among the most common root causes of real incidents, and almost all of them are cheap to fix once visible.
Leaving them unaddressed means failed audits, blocked enterprise deals, and avoidable exposure.
Related free & paid tools
| Tool name | Type | Key features | Link |
|---|---|---|---|
| Node crypto.createHmac | Free | Server-side HMAC for webhook verification | Visit |
| SvixOffer | Freemium | Managed webhook sending with signature verification | Visit |
| Stripe webhook signing | Free | Reference implementation of HMAC-signed webhooks | Visit |
Links marked Offer may be partner links. They cost you nothing extra and never affect which tools we recommend.