HMAC Signer

Generate and verify HMAC signatures using cryptographic keys. Supports SHA-256, SHA-384, SHA-512. All processing is client‑side – your keys never leave your device.

✍️ Message (Payload)

🔑 Secret Key

Algorithm

Output Format

📎 Signature (Result)

📝 Message to Verify

🔑 Secret Key (same)

🔍 Signature to Verify

📖 How to Use HMAC Signer (Step by Step)

Step 1: Enter a secret key and the message (payload) you want to sign.
Step 2: Choose the hash algorithm (SHA-256, SHA-384, or SHA-512) and output format (hex or Base64).
Step 3: Click "Generate HMAC Signature" – the signature appears in the left panel.
Step 4: To verify a signature, paste the original message, secret key, and the signature into the right panel.
Step 5: Click "Verify Signature" – the tool confirms if the signature matches.

💡 Why Use HMAC?

✔️ HMAC ensures message integrity and authenticity using a shared secret.
✔️ Widely used in API authentication (e.g., AWS signatures, webhooks).
✔️ All operations happen locally in your browser – your secret never leaves your device.

💡 Pro Tip: Use the "Load Example" button to try a sample message and secret. The tool will auto‑fill the verification panel for you.

🔒 100% client‑side • Your secret never uploaded • SHA-256/384/512 • Zero tracking