HMAC Generator

Processing: API. Processed by cent-ai's API: sent to our server, held in memory, never stored.

Enter text and a secret key to generate an HMAC-MD5, HMAC-SHA1, HMAC-SHA256, or HMAC-SHA512 digest. Nothing you enter here is stored or logged.

How to use it

  1. Enter the text to authenticate and a secret key.
  2. Choose an algorithm — SHA-256 is selected by default.
  3. The digest appears automatically, or select “Generate HMAC” to run it immediately.

Example

Select “Use example” above to load sample text, then enter any secret key.

Privacy and security

  • Input and secret are sent to our API only to compute the digest; neither is ever persisted or logged.
  • Requests are not included in analytics or error reporting.
  • Prefer a test or throwaway key over a real production secret where possible — see the FAQ.

Limitations

  • MD5 and SHA-1 are offered for legacy compatibility only.
  • Authenticates text input only, not files.

FAQ

What's the difference between this and the Hash Generator?

A plain hash has no key — anyone can compute it. An HMAC is keyed: only someone who knows the secret can produce (or verify) the correct digest, which is what webhook signature verification and API request signing rely on.

Should I paste a real production secret into this tool?

We recommend using a test or throwaway key where possible. The secret is sent to our API only to compute the digest and is never persisted or logged, but treat it with the same caution you would any value sent to a third-party web tool.