HMAC Generator
Generate HMAC (Hash-based Message Authentication Code) using various algorithms. Free online HMAC calculator and tester.
What is HMAC?
HMAC (Hash-based Message Authentication Code) is a specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key. It provides a way to verify both the data integrity and the authenticity of a message.
Common Use Cases
- API Authentication: Securing API requests with HMAC signatures
- Message Integrity: Ensuring messages haven't been tampered with
- Digital Signatures: Creating secure signatures for data
- Blockchain: Securing transactions and data
- File Verification: Verifying file integrity
Supported Algorithms
- SHA-1: 160-bit hash value
- SHA-224: 224-bit hash value
- SHA-256: 256-bit hash value (recommended)
- SHA-384: 384-bit hash value
- SHA-512: 512-bit hash value
- MD5: 128-bit hash value (not recommended for security)
- RIPEMD160: 160-bit hash value
Security Best Practices
- Use a strong, random secret key
- Keep your secret key secure and private
- Prefer SHA-256 or stronger algorithms
- Avoid MD5 for security-critical applications
- Use a key length appropriate for your chosen algorithm
Features
Multiple Algorithms
Support for various hash functions including SHA-256, SHA-512, and more. Choose the algorithm that suits your needs.
Real-time Generation
See HMAC updates instantly as you type. Get immediate feedback for your changes.
Easy Copy
Copy generated HMAC with one click. Ready to use in your application or testing.
Security
All processing happens in your browser. Your data never leaves your device.
How to Use
Enter your message in the input field
Provide your secret key
Select your preferred hash algorithm
Copy the generated HMAC
Common Use Cases
Development
- API authentication
- Message integrity
- Digital signatures
- Secure communication
- Data verification
Security
- Request signing
- Token generation
- Data authentication
- Integrity checking
- Tamper detection
Understanding HMAC
What is HMAC?
HMAC (Hash-based Message Authentication Code) is a specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key. It provides a way to verify both the data integrity and authenticity of a message.
How HMAC Works
HMAC uses two passes of hash computation. The secret key is first used to derive two keys – inner and outer. These are then used in combination with the message to create a final hash that can only be verified with the same secret key.
Frequently Asked Questions
Which hash algorithm should I use?
SHA-256 is recommended for most applications as it provides a good balance of security and performance. However, if you need extra security and performance isn't a primary concern, SHA-512 is a good choice.
Is this tool secure?
Yes, this tool performs all calculations in your browser. Your message and secret key are never sent to our servers. However, for production use, you should implement HMAC generation in your own secure environment.
What's the difference between HMAC and regular hashing?
While regular hashing only provides integrity checking, HMAC adds authentication through the use of a secret key. This means not only can you verify the data hasn't changed, but also that it came from someone with access to the key.