Random Number Generator – No Repeats

How this random number generator works

A random number generator chooses a value from a range without asking you to make the choice yourself. Enter the smallest and largest whole numbers you want to include; both endpoints are possible results. Quantity lets you draw one number or build a list of up to 1,000. Leave repeats off when every number in one list must be different. Turn them on when repeated values are part of the task. The tool checks that a unique draw fits inside the range before it starts. You can use the 1–10, 1–100 and 1–1000 presets to avoid typing common boundaries.

There are two common ways computers produce random values. A pseudo-random generator follows an algorithm from an initial seed, so the same seed can reproduce the same sequence. True random systems gather uncertainty from physical events. This tool uses the browser's Web Crypto API, which provides cryptographically strong random values through the device and browser; it does not claim to expose a directly measured physical source. It also rejects out-of-range values during conversion, avoiding the uneven distribution that a simple remainder calculation can introduce.

Where a number draw helps

For a giveaway with numbered entries, draw distinct ticket numbers and keep a separate record of the eligible entries and winners. In a classroom, number questions or students and let a draw choose the next prompt or turn. For a game, use a small range to decide an order or select a challenge. For simple sampling, assign IDs to items and choose a subset without repeats. You can also create practice data for a spreadsheet or coding exercise. These are selection aids; the tool does not verify eligibility, provide a permanent audit record, or change the odds in a lottery.

Choose Asc or Desc to make a long result easier to scan. Sorting changes only the display order; it does not redraw the numbers. Copy all sends the current list to your clipboard. The text download is handy for notes, while CSV puts one number per row for a spreadsheet. A short history shows the five latest draws during this visit. It clears when you reset or leave the page, so save any result you need to keep. For text entries rather than numbered ones, try the random wheel.