Random Number Generator

How It Works

Set the minimum and maximum, choose how many numbers to generate (up to 500), and pick your output format. Press Generate and the tool draws each number from your browser's cryptographic random number generator — the same engine used to create passwords and encryption keys. Every number lands uniformly inside your range, with no bias from modulo arithmetic.

Where the randomness comes from

The tool calls crypto.getRandomValues() with a 32-bit buffer and uses rejection sampling: if a drawn value falls outside the largest multiple of your range that fits in 32 bits, it is discarded and redrawn. This removes modulo bias, so every integer in your range has exactly the same probability of being picked.

Unique or with repeats

With "Remove duplicates" on, generated numbers are tracked in a set and repeats are redrawn until every result is distinct. This requires your range to be at least as big as the count — if max − min + 1 is smaller than the number you asked for, the tool stops and tells you. With the option off, numbers may repeat, just like drawing balls with replacement.

Negative ranges

The range is simply an integer interval. Set the minimum to a negative value (e.g. -50 to 50) and negatives come out naturally. Only requirement: maximum must be greater than minimum.

Frequently Asked Questions