HMAC Generator

Generate HMAC message authentication codes

Input

Enter message and secret key

Result

HMAC digest output

HMAC digest will appear here...

About HMAC

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

Generate keyed-hash message authentication codes (HMAC) using industry-standard algorithms. Paste your message and secret key to produce a cryptographically secure HMAC hash. All processing uses the Web Crypto API in your browser — nothing is sent to any server.

Key Features

  • SHA-256, SHA-384, SHA-512 algorithm support
  • Web Crypto API — zero server processing
  • Hex-encoded output
  • Copy with one click
  • Instant real-time generation

How to HMAC Generator Online

  1. 1

    Enter message

    Paste the text you want to authenticate.

  2. 2

    Enter secret key

    Provide the shared secret key.

  3. 3

    Select algorithm

    Choose SHA-256, SHA-384, or SHA-512.

  4. 4

    Copy HMAC

    Click generate and copy the hex output.

Common Use Cases

  • API request signing (AWS Signature V4, Stripe webhooks)
  • Webhook payload verification
  • Message authentication in distributed systems
  • Token-based authentication schemes

Frequently Asked Questions

Is my data sent to a server?
No. All HMAC computation is done entirely in your browser using the Web Crypto API.
What is HMAC?
HMAC (Hash-based Message Authentication Code) combines a cryptographic hash with a secret key to verify both data integrity and authenticity.

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