HMAC Generator
Sign messages with HMAC-SHA1, SHA-256, SHA-384 or SHA-512 — perfect for webhook signatures and API authentication.
WebCrypto in your browser Text / Hex / Base64 keys Hex + Base64 + Base64URL
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All HMAC computation happens locally using the WebCrypto API. Your secret never leaves the browser.
What it does
Every common algorithm
HMAC-SHA1, SHA-256, SHA-384, SHA-512 — exactly what Stripe, GitHub, Slack and AWS use to sign webhooks.
Flexible keys
Provide the secret as plain text, hex, or Base64 / Base64URL — useful when your provider gives you a binary key.
Private
Computed locally with WebCrypto. Your secret and message never leave the browser.
Frequently Asked Questions
Quick answers about the HMAC generator.
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