About HMAC Generator
Generate HMACs online for API request signing and webhook verification. Choose common digests such as SHA-256 or SHA-512 and keep keys plus payloads local while you debug signatures. Encoding helpers (UTF-8, hex, Base64) help match provider docs without sending secrets to a remote signer.
What stays local: API secrets and payloads you sign.
What you can do with HMAC Generator
- HMAC with SHA-256, SHA-512, and more
- UTF-8, hex, or Base64 input modes
- Built for API and webhook signing tests
- Keys and payloads stay on-device
How to use HMAC Generator
- Enter key and message. Paste your HMAC secret and the string to sign.
- Pick algorithm and encoding. Match the provider’s digest and input encoding.
- Copy the signature. Use the HMAC in headers or webhook tests.
Privacy
What stays local: API secrets and payloads you sign. DevTooKit is local-first — no signup wall, no server-side processing for this tool, and no watermark on results.
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FAQ — HMAC Generator
Privacy, offline use, and how this free online tool works.
Are my HMAC secrets uploaded?
No. Signing runs locally in your browser.
Which algorithms are supported?
Common options include SHA-256 and SHA-512 — check the tool UI for the full list.
Is this free?
Yes — free online HMAC generation with no account.