ToolVaults

Random Number Generator

Generate random numbers in any range. Integers or decimals, unique or with repeats, Math.random or Web Crypto for cryptographic randomness.

Runs 100% in your browser — nothing is uploaded.

Frequently asked

Math.random vs cryptographic?

Math.random is fast but predictable — never use it for security. Cryptographic mode uses crypto.getRandomValues, which is the browser's CSPRNG (the same one used for HTTPS handshakes).

What does "unique" mean?

No number appears twice in the output. If you ask for more unique integers than exist in the range, you get an error.

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