Enter a message and secret key to compute HMAC-SHA256, HMAC-SHA384, or HMAC-SHA512 hex digests with WebCrypto on your device. Secrets are never uploaded.

How to use this tool

1. Enter the message body. 2. Enter the shared secret. 3. Select HMAC-SHA256, SHA384, or SHA512. 4. Copy the hex digest into webhook signatures or API auth headers.

Worked example

Example: message "hello" with secret "key" under HMAC-SHA256 produces a stable hex digest you can compare to your server’s signature.

How it works

Enter a message and secret key, then choose HMAC-SHA256, HMAC-SHA384, or HMAC-SHA512. The hex digest is generated with WebCrypto on your device.

Limitations

Results are based on the inputs you provide and may not cover every edge case. This tool is for general use and is not professional advice.

Privacy and file handling

Your data stays on your device and is not uploaded.

FAQ

Frequently asked questions

Is HMAC Generator free?

Yes. It is free to use and you do not need to sign in or create an account.

Is my data private?

See the privacy note on this page. Many tools run on your device; some heavier file tools may use secure temporary processing when required.

Can I use HMAC Generator on mobile?

Yes. Open this page on your phone or tablet, enter your inputs, and use the on-screen controls.

Page last reviewed: March 1, 2026

Related tools

Hash Generator

JWT Verifier

File Checksum Calculator

Base64 Encoder & Decoder

JWT Encoder

JSON Formatter

JSON Compare

XML Formatter