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Security and Data Tools

HMAC Generator

Sign a message with HMAC-SHA-256, SHA-384, or SHA-512 using Web Crypto.

Browser workspace

HMAC Generator

⌘ / Ctrl + Enter to run
ImportantHMAC authenticates a message with a shared secret. The message and secret remain only in this tab and are never persisted.
The secret remains in this browser tab and is never stored.
Privacy-first processing

Your data stays private. All processing happens locally in your browser. Nothing is uploaded to our servers.

Built for real work

Why use HMAC Generator?

Sign a message with HMAC-SHA-256, SHA-384, or SHA-512 using Web Crypto. Processing stays in the current browser tab so the source remains private.

Web Crypto HMAC signing
Three SHA-2 digest sizes
Hexadecimal or Base64 output

How to use it

  1. Enter the message and secret key.

  2. Choose algorithm and output encoding.

  3. Select Generate HMAC.

Common use cases

Verify webhook signing logic

Generate test signatures for API clients

Example

message to authenticate

Frequently asked questions

What does HMAC Generator do?

Sign a message with HMAC-SHA-256, SHA-384, or SHA-512 using Web Crypto. Processing stays in the current browser tab so the source remains private.

Is my message uploaded?

No. Your message is processed locally by browser APIs and is never sent to DevTools Hub.

Can I use HMAC Generator without an account?

Yes. HMAC Generator is free, works without registration, and supports modern desktop and mobile browsers.

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