HMAC Generator
/hmac-generatorGenerate HMAC-SHA1, HMAC-SHA256, and HMAC-SHA512 signatures with custom keys. Browser-only, secrets never leave.
Signed webhook payloads and API calls rely on HMAC signatures, which are tedious to verify by hand. This generator computes HMAC-SHA1, HMAC-SHA256, and HMAC-SHA512 signatures for any text and key. You can format the output as hex or base64. Because signing runs locally, your key never leaves the page.
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FAQ
Frequently asked questions
Everything you need to know about hmac generator.
Which algorithms are supported?
HMAC with SHA-1, SHA-256, and SHA-512 is supported, and you can choose between hex and base64 output formats for the resulting signature.
Can I use my own secret key?
Yes. A custom secret key field lets you supply any passphrase or byte string, and the signature is computed from that exact key using the Web Crypto API.
Is my secret key safe?
Yes. All hashing runs locally in your browser and nothing is transmitted, so your key and message never leave your device, even if you are testing production credentials.
What is HMAC used for?
HMAC verifies message integrity and authenticity between parties that share a secret key. It is commonly used in API request signing and webhook validation.
Does it hash files or only text?
The tool accepts text and secret key inputs only. For hashing a file's contents you would need the file hash tool, which streams binary data in chunks.
Why do I need an output format choice?
Hex output is compact and easy to compare, while base64 is shorter for the same bytes and is the format many APIs expect in headers. The choice affects length only.
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