Security utility

HMAC Generator

Generate keyed HMAC values in your browser for message verification, API signing workflows, token review, and development testing with SHA-256, SHA-384, or SHA-512 options.

Generate a keyed digest using the selected algorithm.

What this tool is useful for

This HMAC generator is useful for signed API request testing, webhook verification checks, development workflows, and message integrity scenarios where a shared secret is part of the process.

Common mistakes

Common mistakes include using the wrong algorithm, mismatching the secret key, or altering whitespace in the signed payload. Even a tiny change in the message or key will produce a completely different HMAC value.

Related workflows

This fits into API integrations, test payload signing, webhook review, authentication debugging, and development environments where message signing needs to be checked quickly without leaving the browser.