HMAC Generator

Generate HMAC hashes securely in your browser.

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HMAC Generator
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About the HMAC Generator Tool

We created this tool to provide a fast, secure, and user-friendly way to generate HMACs (Hash-based Message Authentication Codes). An HMAC is a type of digital signature created using a cryptographic hash function and a secret key. It's used to verify both the data integrity and the authenticity of a message simultaneously.

To make this the best tool for the job, we designed it to be completely client-side. It uses the well-trusted CryptoJS library to perform all calculations in your browser. This means your message and, more importantly, your secret key are never sent to our servers, ensuring your data remains 100% private and secure. We also included all the standard hashing algorithms (SHA-256, SHA-512, etc.) and output formats (Hex, Base64) that developers need.

How to Use the Tool

  • Enter the data or message you want to sign into the "Input Message" box.
  • Enter your private "Secret Key" in the field below it.
  • Choose your desired hashing Algorithm (SHA-256 is a strong, common choice).
  • Select your preferred Output Format (Hex or Base64).
  • The generated HMAC will appear in the output box, updating live as you type.

Frequently Asked Questions

What is HMAC used for?

HMAC is widely used to secure web services and APIs. For example, when you communicate with a payment gateway or a cloud service API, they often require you to sign your request with an HMAC using a secret key they provide. This proves to the server that the request is genuinely from you and that it hasn't been tampered with in transit.

Is this HMAC generator secure? Can I use my private keys here?

Yes. This tool is completely secure for generating HMACs with private keys. All the cryptographic calculations happen directly on your computer, inside your web browser. Your secret key is never transmitted over the internet or stored on our servers.

What is the difference between an HMAC and a regular hash (like SHA-256)?

A regular hash (like SHA-256) can only verify data integrity. Anyone can create the same hash from the same input. An HMAC combines the message with a secret key before hashing. This means that only someone who possesses the secret key can generate a valid HMAC. This verifies both integrity (the data wasn't changed) and authenticity (the sender knew the secret key).

Which algorithm should I use?

For most modern applications, HMAC-SHA256 is the recommended standard. It provides a strong level of security and is widely supported. HMAC-SHA512 is even stronger but may be overkill for some applications. HMAC-MD5 and HMAC-SHA1 are older and considered less secure, and should only be used if required by a legacy system.

What's the difference between Hex and Base64 output?

Hex (Hexadecimal) and Base64 are two different ways of encoding the raw binary output of the hash function into a readable text string. Hex uses characters `0-9` and `a-f`, while Base64 uses `A-Z`, `a-z`, `0-9`, `+`, and `/`. The format you should use depends entirely on what the receiving system or API expects.

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