Random Number Generator

Truly random numbers

Set a minimum and maximum, choose integers or decimals, and pick how many numbers to generate. The no-duplicates option is great for raffles, lotteries and random sampling. Unlike basic generators, this tool uses crypto.getRandomValues for high-quality randomness.

Options

• Any range of integers or decimals
• Generate up to 1,000 numbers at once
• Optional unique (no-duplicate) results

Key features at a glance

• Generate random integers or decimals in any range
• Produce one or up to 1,000 numbers at once
• Optional no-duplicates mode for unique results
• Uses the browser's cryptographically secure random source
• One-click copy of the generated numbers
• Runs entirely in your browser, even offline

What makes randomness high quality

Not every random number generator is equal. The Math.random() function built into JavaScript is a pseudo-random generator: fast and fine for casual use, but its sequence is predictable enough that it should never be relied on where fairness or security matters. This tool instead uses crypto.getRandomValues, the browser's cryptographically secure source, which produces numbers that cannot be predicted from previous outputs.

Quality also depends on the numbers being unbiased — each value in your range equally likely. A careless implementation that maps a random byte onto a range with simple division introduces subtle bias, making some numbers slightly more common. Proper generators use rejection sampling to keep every outcome equally probable. For raffles, sampling, and anything where fairness counts, that combination of unpredictability and even distribution is what you want.

Drawing with and without duplicates

There is an important difference between sampling with replacement and without. With replacement, every draw is independent and the same number can come up more than once — appropriate for simulating dice rolls or any situation where repeats are natural. This is the default behavior when the no-duplicates option is off.

Without replacement, each number can appear only once, which is what you need for a raffle where one ticket cannot win twice, for assigning unique IDs, or for picking a random subset of a list. The no-duplicates mode enforces this, drawing distinct values until your request is filled. Choosing the right mode matters: using duplicates where uniqueness is required can produce unfair or invalid results.

Integers versus decimals

The generator can produce whole numbers or decimals depending on your need. Integers are the right choice for counting-based tasks: lottery numbers, dice, raffle tickets, array indices, or picking a winner from a numbered list. Setting a clear minimum and maximum defines the inclusive range from which each integer is drawn.

Decimals are useful when you need continuous values — random coordinates, simulated measurements, test data, or probabilities. Because decimals can take many more values within a range, duplicates are far less likely even without the no-duplicates option. Matching the type to your purpose ensures the output is directly usable rather than needing conversion.

Tips for using the random number generator

• Turn on no-duplicates for raffles, draws, and unique sampling
• Leave duplicates allowed when simulating dice or independent events
• Use integers for counting tasks and decimals for continuous values
• Set the minimum and maximum to define an inclusive range
• Generate a batch at once when you need several numbers

Why choose our random number generator?

Our generator is completely free with no signup, no limits, and no subscription. It runs entirely in your browser using a cryptographically secure source, so numbers are generated locally and never sent to a server, and the tool works offline.

It is one of more than 200 free tools on ToopTools, and you can pin it to your My Workspace, a personalized workspace where you keep the tools you use most in a single dashboard. Beside the other math tools, it gives you fair, high-quality randomness whenever you need it.

Common use cases

People use the random number generator to run raffles and giveaways, pick a winner from a numbered list, draw lottery-style numbers, and randomly sample data. The no-duplicates mode makes it fair for any draw where each entry can only be chosen once.

Developers and researchers use it to generate test data, random coordinates, and sample sets, and teachers use it to pick students or create randomized problems. Because it offers integers or decimals and batches of any size, it adapts to everything from a single coin-flip to a thousand-value sample.

Is the random number generator free?

Yes. It is completely free with no account, no sign-up, and no usage limits. Generate as many numbers as you like at no cost.

Is the randomness secure and fair?

Yes. It uses crypto.getRandomValues, the browser's cryptographically secure random source, with unbiased sampling, so the numbers are unpredictable and every value in the range is equally likely.

Can I generate numbers with no duplicates?

Yes. Enable the no-duplicates option and every generated number will be unique, which is ideal for raffles, draws, and selecting a random subset where repeats are not allowed.

How many numbers can I generate at once?

You can generate up to 1,000 numbers in a single batch, each within your chosen range, and copy them all with one click for use elsewhere.

Can it generate decimals as well as integers?

Yes. Choose integers for whole-number tasks like lottery numbers and dice, or decimals for continuous values such as coordinates and simulated measurements.

Why not just use Math.random()?

Math.random() is a pseudo-random generator that is fast but predictable, so its output can in principle be reconstructed and should not be used where fairness or security matters. This tool uses crypto.getRandomValues, a cryptographically secure source, which produces genuinely unpredictable numbers suitable for draws and sampling.

Is the range inclusive of the minimum and maximum?

Yes. The minimum and maximum you set are both possible results, so a range of 1 to 6 can produce any value from 1 through 6 inclusive, just like rolling a die.

Are the numbers kept private?

Yes. Generation happens entirely in your browser and nothing is uploaded, so the numbers stay on your device and the tool works without an internet connection.

How do I generate a random number in a range?

Set the minimum and maximum values and the tool instantly picks a random number between them, inclusive of both ends. You can generate several at once, allow or forbid duplicates, and choose whole numbers or decimals.

Does the random number generator work offline?

Yes. The numbers are generated entirely in your browser using secure randomness, so once the page has loaded the tool works without an internet connection, and nothing is uploaded — each result is created locally on your device.