Online SHA-256 Hash Generator (Supports HMAC)

Input String

HMAC Key (Optional)

Output Format:

Lowercase (64 characters)

Uppercase (64 characters)

SHA-256 Hash Value

Tool Description

SHA-256 is a member of the SHA-2 (Secure Hash Algorithm 2) family and is currently the most widely used secure hashing algorithm. It maps data of any length to a fixed 256-bit (64 hexadecimal character) hash value. SHA-256 is considered secure and was designed by the U.S. National Security Agency (NSA).

Recommended

SHA-256 is the industry standard for digital signatures, password storage (with salt), blockchain (e.g., Bitcoin), and various security protocols. In all new security applications, SHA-256 or stronger algorithms (like SHA-512) should be preferred.

Standard SHA-256: Perform standard SHA-256 hash calculation on the input string.
HMAC-SHA256: When a key is provided, calculate a Hash-based Message Authentication Code (HMAC). This is a modern standard method for protecting data integrity and performing authentication, widely used in JWT, API signatures, etc.
Native Implementation: This tool uses the browser's built-in `SubtleCrypto` API, requiring no third-party libraries—secure and efficient.