Security & Privacy 100% Local Processing Limit: 10 MB

HMAC Keyed-Hash Authenticator

Generate Hash-based Message Authentication Codes (HMAC) with secret keys using SHA-256, SHA-384, SHA-512, or SHA-1.

Sponsor Space

1. HMAC Inputs

2. Calculated Signature

Calculated natively via Web Crypto API in your browser.

Sponsor Space

How to Use the HMAC Keyed-Hash Authenticator

  1. 1
    Enter or paste your raw payload / message text.
  2. 2
    Enter the shared Secret Key.
  3. 3
    Select the hashing algorithm: SHA-256, SHA-384, SHA-512, or SHA-1.
  4. 4
    Choose output format: Hexadecimal (lowercase/uppercase) or Base64.
  5. 5
    Copy the verified HMAC signature to validate webhooks or sign API requests.

Practical Example & Use Case

Common Real-World Scenario

Generating or verifying GitHub, Stripe, or Shopify webhook signatures using your endpoint secret.

Technical Notes & Limitations

Browser Engine Architecture

Computed client-side using the native browser Web Crypto API (crypto.subtle.sign). Zero key exposure.

Frequently Asked Questions

How does HMAC differ from a regular SHA hash?

A regular hash only verifies data integrity. HMAC incorporates a secret key, simultaneously authenticating data integrity AND the sender identity.

Recommended Utilities

Related Security & Privacy Tools

Explore complementary browser-based utilities to streamline your workflow.

View All Security & Privacy Tools →
Security

File and Text Hash Generator

Compute cryptographic hashes (SHA-256, SHA-1, SHA-384, SHA-512, MD5) for text and local files.

Try Tool →
New

File Checksum & Hash Comparator

Compare two files or verify a downloaded file against an official SHA-256 or MD5 checksum to ensure software integrity.

Try Tool →
Essential

JWT (JSON Web Token) Decoder

Decode and inspect JSON Web Tokens locally in your browser. View formatted header, payload, and live expiration status.

Try Tool →