freetoolsY

HMAC Generator

Developer

Generate HMAC-SHA256 or HMAC-SHA512 signatures online free using the Web Crypto API. Get both hex and Base64 forms instantly; everything runs in your browser.

Using the Web Crypto API — the key and message never leave your browser.

What is an HMAC Generator?

An HMAC Generator computes an HMAC-SHA256 or HMAC-SHA512 signature for your message using a secret key, and shows the result in hex and Base64. It is commonly used to verify the integrity and origin of API requests.

How to use it

  • Paste your message text and your secret key.
  • Choose SHA-256 or SHA-512 as the hash function.
  • Copy the resulting signature in hex or Base64.

A security note

The signature depends on the exact bytes of your message. Use the same signing settings as the service you are talking to, and never paste production secrets on untrusted machines — this tool runs entirely in your browser.

FAQ

  • Is HMAC the same as simple hashing? No — HMAC keys the hash with a secret, so it proves authenticity, not just integrity.
  • Does it work on files? Not directly; hash the file contents first, then sign the hash.
  • Is my secret key safe? The key is processed locally in your browser and never transmitted.

Frequently Asked Questions

Similar tools

View all tools

Popular tools

View all tools

Want to share what you created? Try linklyhub.com for a short, clean link.