What HMAC-SHA-256 Calculator does
Calculate HMAC-SHA-256 for a UTF-8 message and UTF-8 key using the browser Web Crypto API.
Input and output contract
Key and message remain in browser memory and the key must not be empty. A 64-digit uppercase hexadecimal HMAC.
Safe workflow
Enter the exact message and key text and calculate locally. SaveEditor processes this operation locally in the browser and does not infer a game format from the input.
Important limitations
This Tool calculates a MAC only; it does not store secrets, derive keys, or verify application-specific authentication protocols. If a protocol uses raw binary keys/messages instead of UTF-8 text, use a format-specific implementation.