Random number generator.

Without a seed they come from crypto.getRandomValues, the browser's cryptographic generator. Each value is drawn by rejection sampling, so none in the range is likelier than another, as a plain modulo would make some.

A seed switches to a seeded generator (sfc32, started from a hash of the text), so the same seed and settings give the same draw on any machine. That suits a draw others can check, or a test that must repeat. A seeded draw isn't for secrets.

Each number is drawn from those not drawn yet, a partial Fisher–Yates shuffle of the range, so a draw like 6 of 49 is fair. You can't ask for more unique numbers than the range holds; the tool says how many it has.

On a grid of the places you choose: with 2 places from 0 to 1, each of 0.00, 0.01 and so on to 1.00 is equally likely. Up to 10 places.

Press the 6 of 49 preset: six different numbers from 1 to 49, sorted. Change the max and the count for another game.

Up to 10,000 in one draw, with their count, sum, mean, lowest and highest listed under them. Copy them separated by commas, spaces or new lines, or download a text or CSV file.

No. The numbers are drawn in your browser and the page makes no request.

No. The Random number generator is free and opens without a sign-in, an account or an install.

The Random number generator keeps nothing on a server; only the invoice generator saves its draft, in this browser's localStorage on your device. Nothing else is saved, and nothing is sent to shadcn.io.

Up to 10,000 numbers a draw, 10 decimal places, and bounds within ±9,007,199,254,740,991, the largest whole numbers a browser counts exactly. With No repeats on, the range must hold as many numbers as you ask for.

1 to 10 and 1 to 100 for one number, 6 of 49 for a lottery draw (six different numbers, sorted), and 0 to 1 for one decimal with four places.

So the page opens on an example: a draw from a fixed seed, as the status line says. Press Generate for a fresh draw from crypto.getRandomValues, or type your own seed to repeat a draw.

Closest to the Random number generator: Dice roller, Coin flip, Random string generator, Password generator. Each opens on its own page, free and in the browser.

The Random number generator is one of 20 in its group. The group's page, /tools/math, lists them all.

The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.