Random Number Generator — Fair Numbers in Any Range

What is a Random Number Generator?

A Random Number Generator (रैंडम नंबर जनरेटर), often called an RNG, picks numbers so that nobody — not you, not the tool, not the person watching — can predict or influence the result. People use one to choose a lucky-draw winner, decide who goes first, pick a question number in class, sample rows from a spreadsheet, create test data or simply settle an argument. Doing it in your head is never truly random: humans favour certain numbers (7 is famously popular when people are asked to “pick a number from 1 to 10”) and avoid repeats that real randomness produces all the time.

This free tool generates one number or up to 10,000 in any range you choose, whole numbers or decimals, with or without repeats. It uses your browser's cryptographically secure random generator and a technique called rejection sampling, so every value in your range has exactly the same chance. Nothing is sent to a server — the numbers are created on your own device.

Key Features

• Any range — positive, negative or both, up to about ±9 quadrillion.
• Bulk generation — 1 to 10,000 numbers per click.
• No-repeats mode for raffles, seating plans and sampling.
• Decimals — 0 to 4 decimal places.
• Sorting — show results from smallest to largest.
• Presets — 1–10, 1–100, dice, 4-digit PIN, lottery 6 of 49, 0 or 1.
• Stats — count, smallest, largest, sum and average for multiple numbers.
• Copy, download and history of your last ten results.

How to Use It — Step by Step

1. Set the minimum and maximum. Both ends are included, so 1 to 6 can give 1, 6 or anything in between.
2. Choose how many numbers you want (default 1).
3. Pick decimal places if you need values like 2.5 or 0.073.
4. Tick “No repeats” if each number must be different, and “Sort” if you want them in order.
5. Press Generate (or Enter). Press it again for a fresh result.
6. Copy or download the numbers. The history keeps your last ten results while the page is open.

How the Randomness Works (and Why It Is Fair)

Many simple websites use JavaScript's Math.random(), which is fast but not designed to be unpredictable, and then squeeze its output into a range with a formula that can make some numbers very slightly more likely than others. This tool does two things differently:

• Secure source. It reads random bits from crypto.getRandomValues, which browsers seed from the operating system's entropy pool — the same quality of randomness used to create encryption keys.
• No modulo bias. A 32-bit random value has 4,294,967,296 possibilities. If your range has, say, 10 values, that number does not divide evenly, so a naïve “remainder” approach favours the lowest values by a tiny amount. The tool throws away the few random values that cause this imbalance and draws again (rejection sampling). The result: every value in the range is exactly equally likely.

For unique numbers, the tool uses a Fisher–Yates shuffle when you are picking a large share of the range, and redraws duplicates when you are picking a few numbers from a huge range. Both methods keep every possible combination equally likely.

Common Uses and Settings

A Little Probability

Understanding the odds helps you trust — and explain — a random result:

• Single pick: in a range with N values, each value has a 1 in N chance. From 1 to 6, that is about 16.7%.
• Repeats are normal: with “No repeats” off, drawing 23 numbers from 1 to 365 gives better than a 50% chance (about 50.7%) that at least two are the same — the famous birthday paradox. Seeing a repeat does not mean the generator is broken.
• Lottery odds: there are 13,983,816 different ways to choose 6 numbers from 49, so any one ticket has a 1 in 13,983,816 chance of matching all six.
• No memory: past results never change future ones. After five 7s in a row, the next pick is still exactly as likely to be 7 as anything else.

Random Numbers in Excel or Google Sheets vs This Tool

Spreadsheets can generate random numbers too: =RANDBETWEEN(1,100) returns a whole number from 1 to 100, =RAND() returns a decimal between 0 and 1, and Excel 365 adds =RANDARRAY(rows, columns, min, max, TRUE) for many at once. The catch is that these functions are volatile — they recalculate every time the sheet changes, so your “winner” can silently change when someone edits another cell. Spreadsheet formulas also have no built-in no-repeats option, so unique picks need extra helper columns. This tool gives you a fixed result you can copy, a true no-repeats mode and a visible history, which is easier to show to an audience. A good workflow is to keep your entries in the sheet, generate the row numbers here, and then look them up.

Running a Fair Lucky Draw

Shops, schools, societies and YouTube creators often run giveaways. To make yours transparent:

1. Number every entry in a list (a spreadsheet works well) and announce the total.
2. Share your screen or record a video, then set the range from 1 to the total.
3. Tick “No repeats” and set “How many” to the number of prizes.
4. Press Generate once and match the numbers to the list.
5. Keep the recording so anyone can verify the result later.

If your entries are names rather than numbers, our Random Name Picker lets you paste the names directly, and Spin the Wheel adds a fun on-screen animation.

Who Uses a Random Number Generator?

• Teachers calling on students or assigning question numbers.
• Event organisers and shops drawing raffle winners.
• Researchers and analysts selecting random samples.
• Developers and testers creating test data.
• Gamers replacing dice or cards.
• Families and friends deciding who pays, who drives or what to eat.

Common Mistakes to Avoid

• Forgetting the ends are included. 1 to 10 includes both 1 and 10.
• Allowing repeats in a raffle. Tick “No repeats” so one ticket cannot win twice.
• Re-rolling until you like the answer. That defeats the purpose — decide in advance that the first result counts.
• Using it for real passwords. A number range is a weak secret; use a password generator with letters and symbols.

Troubleshooting

• “Only N different values exist” — you asked for more unique numbers than the range contains. Widen the range or allow repeats.
• “No number with that many decimal places” — the range is narrower than one step, for example 1.21 to 1.22 with 1 decimal.
• Big list looks slow to copy — use Download .txt for very large batches.

Quick Glossary

• RNG: random number generator.
• CSPRNG: cryptographically secure pseudo-random number generator.
• Uniform distribution: every value equally likely.
• Modulo bias: a small unfairness caused by squeezing random bits into a range with a remainder.
• Rejection sampling: discarding and redrawing values that would cause bias.
• Fisher–Yates shuffle: an unbiased way to shuffle a list.

Why Use This Random Number Generator?

It combines secure randomness, mathematically fair ranges, unique and bulk modes, and simple presets in one fast page — free, private and ready for classrooms, giveaways and data work.

Random Number Generator — Key Facts

Frequently Asked Questions

Explore More Prompt Minds Tools

Random Number Generator works great alongside our other free tools. Every Prompt Minds tool runs entirely in your browser — no sign-up, no uploads, no watermarks. Browse all free tools.