HMAC Generator

Generate and verify HMAC signatures for message authentication

HMAC Calculator

Hexadecimal
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Base64
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HMAC-SHA1

160-bit output, legacy compatibility

HMAC-SHA256

256-bit output, recommended for most uses

HMAC-SHA384

384-bit output, stronger security

HMAC-SHA512

512-bit output, highest security

100% Client-Side Processing

Your keys and messages never leave your browser. All HMAC computations happen locally using the Web Crypto API.

About HMAC

What is HMAC?

HMAC (Hash-based Message Authentication Code) is a cryptographic construction that combines a secret key with a message hash to provide both data integrity and authentication. It's widely used in API authentication, JWT signatures, and secure communication protocols.

How HMAC Works

HMAC(K, m) = H((K' xor opad) || H((K' xor ipad) || m)) Where: - K = Secret key - m = Message - H = Hash function (SHA-256, etc.) - K' = Key padded to block size - opad = Outer padding (0x5c repeated) - ipad = Inner padding (0x36 repeated)

Common Use Cases

Security Considerations

Example: API Signature

// JavaScript example const key = "your-secret-key"; const message = "timestamp=1234567890&data=example"; const signature = HMAC_SHA256(key, message); // Result: 7a1f2b3c4d5e6f...

What is HMAC Generator?

HMAC Generator is a free online tool that creates hmac with customizable options. Whether you're a developer, designer, or professional, this tool helps you generate hmac quickly and efficiently right in your browser. No installation, no signup, and no data leaves your device.

How to Use This Tool

  1. Step 1: Enter or paste your input in the provided field
  2. Step 2: Configure any options or settings as needed
  3. Step 3: View the result instantly (or click the action button)
  4. Step 4: Copy the result using the copy button

Common Use Cases

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