HMAC Generator - Generate HMAC Signatures Online

Generate HMAC (Hash-based Message Authentication Code) signatures online for free. Perfect for API request signing, webhook verification, and message authentication. Supports SHA-1, SHA-256, SHA-384, and SHA-512 algorithms.

Multiple Algorithms

Support for HMAC-SHA1, SHA-256, SHA-384, and SHA-512.

Flexible Output

Generate signatures in hexadecimal or Base64 format.

API Authentication

Perfect for signing API requests and verifying webhooks.

Generate HMAC Signature

About HMAC

  • • HMAC (Hash-based Message Authentication Code) verifies data integrity and authenticity
  • • Commonly used for API request signing and webhook verification
  • • Both sender and receiver must have the same secret key
  • • HMAC-SHA256 is recommended for most applications

What is HMAC?

HMAC (Hash-based Message Authentication Code) is a mechanism for calculating a message authentication code involving a cryptographic hash function in combination with a secret key. It can be used to verify both the data integrity and authenticity of a message.

Common Use Cases

  • API Request Signing: Sign API requests to prove they haven't been tampered with
  • Webhook Verification: Verify that webhooks are from the expected source
  • Message Authentication: Ensure messages haven't been modified in transit
  • Session Tokens: Create secure, tamper-proof session identifiers
  • Data Integrity: Verify that data hasn't been corrupted or modified

HMAC Algorithms

AlgorithmOutput SizeUse Case
HMAC-SHA1160 bitsLegacy systems
HMAC-SHA256256 bitsRecommended for most uses
HMAC-SHA384384 bitsHigh security requirements
HMAC-SHA512512 bitsMaximum security

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