Generate HMAC signatures with SHA-1, SHA-256, SHA-384 or SHA-512 using a UTF-8 or hex secret key, output as hex or Base64. Computed in your browser, so your key never leaves it.
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- Computed in your browser with Web Crypto — your key is never sent to a server
- SHA-1, SHA-256, SHA-384 and SHA-512 with hex or Base64 output
- UTF-8 or hex secret keys, updated live as you type
How it works
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1
Set the options — length, quantity, character set, or template.
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2
The result generates instantly in your browser.
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3
Regenerate as many times as you like.
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4
Copy the result to your clipboard.
Why use this tool
Every dev utility, one place
Format, convert, encode, decode, and generate — no more juggling ten tabs.
100% private, always
Every tool runs in your browser — your code and data are never sent anywhere.
Works on any device
Runs on Windows, Mac, Linux, iOS, and Android — nothing to install.
Instant results
No queues, no build step — results update as you type.
Built to handle real data
Full Unicode support and RFC-compliant parsing, edge cases included.
Free, always
Free to use, with no rate limits, sign-up, or trial period.
Frequently asked questions
No. The HMAC is computed in your browser with the Web Crypto API; the message and key are never uploaded.
SHA-256 is the common default for API signatures and webhooks. Use SHA-512 or SHA-384 when a provider requires them; SHA-1 is only for legacy systems.
Pick hex when your provider gives the secret as raw bytes written in hexadecimal. An invalid hex key, such as an odd number of characters, shows an inline error.
Yes. An empty message still produces a valid HMAC for the given key.
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