HMAC Generator
Generate HMAC-SHA-256, SHA-384, or SHA-512 authentication codes from UTF-8 text and a key.
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How to use HMAC Generator
Calculate a keyed message authentication code locally for debugging a specified HMAC integration. The key and message are used only in the current tab and are not retained by the application.
- Enter the exact message, a non-empty UTF-8 key, and the agreed SHA algorithm.
- Select Run tool to compute the HMAC authentication code.
- Review the result, then copy it or download the generated file.
Good to know
- Up to 200,000 message characters and 10,000 key characters. Keys are interpreted as exact UTF-8 text, including whitespace, not hexadecimal or Base64.
- Output is a calculation, not a verified authentication decision or key-management system. Keep real secrets private and clear the form after use.
Common questions
Why does a hex-looking key give a different result?
This tool treats the visible characters as UTF-8. An integration that decodes a hex key uses different bytes.
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