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Random Sample Generator | Draw a Simple Random Sample From a List

Draw a fair random sample from your list — with or without replacement, using an unbiased Fisher-Yates shuffle. The survey and testing tool that guarantees every subset is equally likely.

Last updated: June 2026 · Free · No sign-up required

Results

Enter values above and click Calculate to see your result instantly.

Quick reference

Need	Setting
Pick 1 winner from entries	Sample size 1, without replacement
Survey 30 of 500 customers	Sample size 30, without replacement
Bootstrap resample of a dataset	Sample size = n, with replacement
Assign 10 people to 2 teams	Sample 5, the rest form team 2

info Random Sample Generator

Free generators calculator — enter your numbers and get an instant, accurate result.

info Private by design

Everything runs locally in your browser. No uploads, no accounts, no tracking.

info Works everywhere

Fully responsive and mobile-friendly — calculate on any device, any time.

info Educational

Includes the formula and step-by-step explanation so you understand the math, not just the answer.

Interpretation guide

Method	When to use
Without replacement	Winners, audits, surveys — each item can be picked once
With replacement	Bootstrapping and simulations — items can repeat

lightbulb Worked example

Let's say you are using the Random Sample Generator. Draws a simple random sample of any size from your pasted list, with or without replacement. Enter the values that match your situation into the input fields and press calculate — using realistic numbers makes the result directly useful for you.

Result: The calculator instantly applies the formula Each item is selected with equal probability; without replacement uses an unbiased Fisher–Yates shuffle and returns the result with appropriate precision.

What this means: Read the result in the context of what you are measuring. The step-by-step breakdown lets you confirm the math and understand which input most affects the outcome.

Formula & methodology

Formula: Each item is selected with equal probability; without replacement uses an unbiased Fisher–Yates shuffle

The Random Sample Generator is built on a well-established calculation method. It uses the formula Each item is selected with equal probability; without replacement uses an unbiased Fisher–Yates shuffle to turn your inputs into a reliable result. Draws a simple random sample of any size from your pasted list, with or without replacement. The steps are shown on the page so you can follow the reasoning from input to output.

Paste your population — one item per line or comma-separated.
Choose how many to draw and whether items may repeat.
The generator shuffles with the Fisher–Yates algorithm seeded by a cryptographically secure random source and returns the first n items.

Worked example: sampling 3 from a 10-name list gives every name an identical 3-in-10 chance of selection — a textbook simple random sample, free of the ordering bias you get by 'just picking a few'.

Frequently asked questions

How do I generate a random sample?

Paste your list, choose the sample size, and select whether draws can repeat. Each item is selected with equal probability, and without replacement the tool uses an unbiased Fisher–Yates shuffle so every subset is equally likely. The result is a fair sample suitable for surveys, testing, and classroom draws.

What is the difference between sampling with and without replacement?

The Random Sample Generator is free, private, and accurate: it runs entirely in your browser (no uploads, no accounts), applies the standard calculation, and explains each step so you can verify the result. Draws a simple random sample of any size from your pasted list, with or without replacement. There is no limit on usage, and it works on any device.

Is this a true simple random sample?

Yes — every item has an equal probability of selection, and the without-replacement mode uses an unbiased Fisher–Yates shuffle, meaning every subset of the requested size is equally likely. The randomness comes from the browser's cryptographically secure source. This satisfies the definition of a simple random sample for survey and testing purposes.

How large should my sample be?

It depends on the population size and the margin of error you need: larger samples give more precise estimates but with diminishing returns once you pass a few hundred. For a small list, sampling half or more gives good coverage; for large populations, a sample of 200–400 often achieves a ±5% margin at 95% confidence. The tool lets you draw any size and shows the chosen subset clearly.

Can I redraw the sample?

Yes — the draw is recalculated each time you press the button, so you can produce a fresh sample for comparison or reproducibility testing. If you need to reproduce the exact same sample later, note the items drawn or use the seeded mode with a fixed seed. For real research, document the draw method and record the sample before analyzing.

Should I sample with or without replacement?

Choose without replacement for draws where each item can appear only once — prize draws, jury selection, or survey sampling from a customer list. Choose with replacement for simulations and bootstrap-style experiments where repeats are realistic, like modeling repeated dice rolls.

Can someone else reproduce my exact sample later?

No — each draw is freshly random, so the exact same sample cannot be replayed later. If you need a documented, auditable selection (for a raffle or a published study), record the sample size, the method, and the resulting list at the time of the draw.

How are duplicate or blank lines in my list handled?

Duplicate lines are treated as separate entries, so an item appearing twice in your list has double the chance of being picked. Blank lines are ignored, which means you can safely paste a list with empty rows without skewing the draw.

Is the draw genuinely fair, or could it be biased?

Yes — the shuffle uses the Fisher–Yates algorithm, which gives every possible subset exactly equal probability. It uses the device's standard random number source, which is more than fair enough for draws, sampling, and testing, though not certified for cryptography or gambling.

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