HMAC Generator
NewGenerate cryptographic HMAC signatures using SHA-256, SHA-512, MD5, or SHA-1 with custom secret keys
About HMAC Generator
HMAC Generator (Hash-based Message Authentication Code) is a powerful, client-side cryptographic tool designed for backend engineers, API developers, and security personnel. It computes keyed hash message authentication signatures using standard hashing algorithms including SHA-256, SHA-512, SHA-1, and MD5 combined with a secret key.
HMAC signatures are fundamental to modern web security architecture, API payload signing (such as AWS SigV4, GitHub webhooks, Stripe webhooks, and OAuth 2.0), and data integrity verification. All HMAC calculations execute 100% in your local browser memory using Web Crypto APIs, keeping your secret keys and sensitive payloads private.
The tool supports output signature formatting in both Hexadecimal (Hex) and Base64 strings, allowing instant comparison against API gateway signatures and webhook verification headers.
How to Use HMAC Generator
- Enter or generate a secret key in the Secret Key input field.
- Select your preferred output encoding (Hexadecimal or Base64).
- Paste your request payload or plain text message.
- Copy the computed HMAC-SHA-256 or HMAC-SHA-512 signature with one click.
Privacy & Data Security
HMAC Generator processes all operations 100% locally in your web browser memory. Your files, text snippets, and generated outputs are never stored, logged, or uploaded to any remote server.
Frequently Asked Questions
A standard hash (like SHA-256) only verifies data integrity. An HMAC incorporates a secret key alongside the message, verifying both data integrity AND authenticating the identity of the sender who holds the secret key.
HMAC-SHA-256 and HMAC-SHA-512 are the current industry standards for API authentication and webhook signatures. HMAC-SHA-1 and HMAC-MD5 are maintained for legacy system compatibility.
No. The entire HMAC computation takes place locally inside your web browser session using client-side JavaScript and the Web Crypto API. No data is sent to external servers.
Enter your webhook secret as the Secret Key, paste the raw request payload into the message field, select HMAC-SHA-256, and compare the resulting hex output against the signature header.