HMAC Generator — Free Online Tool

Compute HMAC message authentication codes with SHA-1, SHA-256, SHA-384 or SHA-512 and a secret key, in hex or base64.. HMAC Generator is a free online tool from the ToolsRift Developer Tools collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.

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How to use HMAC Generator

Enter your message and secret key, choose a hash algorithm and output format, and the tool computes the HMAC using the Web Crypto API for you to copy.

Frequently asked questions

What is an HMAC?

A keyed hash that proves both the integrity and authenticity of a message — only someone with the secret key can produce a matching code.

How is HMAC different from a plain hash?

A plain hash uses no key, so anyone can recompute it. HMAC mixes in a secret key so the code cannot be forged without it.

Which algorithm should I choose?

SHA-256 is a strong default; use SHA-384 or SHA-512 for extra margin. Avoid SHA-1 for new security-sensitive uses.

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