HMAC Generator

Generate HMAC digests with masked keys. Free, private, runs in your browser.

100% private — your files and text never leave your browser. All processing happens locally on your device.

Message

Secret Key

Keys are masked by default and stay in this tab.

Algorithm

Key input

Output

Enter a key and message, then generate a local HMAC digest.

You might also need

Hash GeneratorGenerate MD5, SHA-1, SHA-256, SHA-512 hashes

JWT DecoderDecode and verify JWT tokens with color-coded display

AES Encrypt / DecryptEncrypt or decrypt text with AES-GCM locally

Password GeneratorGenerate secure random passwords instantly

Generate Message Authentication Codes

HMAC Generator computes SHA-256, SHA-384, or SHA-512 HMAC digests with Web Crypto. It supports text, hex, and base64 keys, plus hex or base64 digest output for API signatures and test vectors.

Masked Key Workflow

The shared secret is masked by default and stays in the current tab state. Convertful does not store keys, messages, or generated digests, and the tool has no remote validation path.

Use The Right Secret Handling

HMAC proves that someone with the same shared secret produced the digest. It does not encrypt the message, and its security depends on protecting the secret outside the browser too.

FAQ

Which HMAC algorithms are supported?

The tool supports SHA-256, SHA-384, and SHA-512 using the browser Web Crypto API.

Can the key be hex or base64?

Yes. Choose text, hex, or base64 key input and export the digest as hex or base64.

Is the key saved?

No. The key is masked by default and stays in browser memory only for the current tab.

Can I hash an empty message?

Yes. Empty messages are supported and reported as zero-length message digests.

Is HMAC the same as encryption?

No. HMAC authenticates a message with a shared secret; it does not hide the message.