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Generate Random Numbers in Any Range Generate random numbers within a custom range with unique-only option.

Random Number Generator illustration
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Random Number Generator

Generate random numbers within a custom range with unique-only option.

1

Set Range

Enter minimum and maximum values for your random numbers.

2

Choose Options

Set quantity and toggle unique-only mode if needed.

3

Generate

Click Generate to produce random numbers based on your settings.

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What Is Random Number Generator?

A Random Number Generator produces random integers within a specified range, allowing users to customize the minimum and maximum values. Developers, data analysts, and researchers use it to generate random numbers for applications such as lotteries, statistical sampling, and game development, where unbiased random selection is crucial. One specific problem it solves is ensuring unique random selections, which is particularly important in simulations or modeling where duplicate values can skew results.

The tool's ability to generate multiple numbers at once, with an option to ensure uniqueness, sets it apart from other number generators. It allows users to specify a quantity of numbers to generate, up to 10,000, and optionally check for uniqueness, which helps prevent duplicates in the output. The code behind it uses a pool of numbers to shuffle and select unique values when this option is enabled, ensuring that the generated numbers are truly random and distinct.

It also features input fields for minimum and maximum values, allowing users to define their own range, such as generating random numbers between 1 and 100. This flexibility makes it a useful Random Number Picker for various applications, including generate random numbers online for simulations or modeling tasks. With its customizable range and unique generation capabilities, the tool provides a reliable way to produce random integers for a wide variety of use cases, from simple random number generator 1 to 100 tasks to more complex statistical analyses.

Why Use Random Number Generator?

  • Custom min/max range for any use case
  • Generate multiple numbers at once (up to 10,000)
  • Unique-only mode prevents duplicates
  • Uses Fisher-Yates shuffle for unbiased unique selection
  • Clean interface — set range, quantity, and generate in one click

Common Use Cases

Lottery & Raffles

Draw unique winning numbers for lotteries, raffles, or giveaways.

Statistical Sampling

Select random samples from numbered datasets for analysis.

Game Development

Generate random values for dice rolls, card draws, or game mechanics.

Random Selection

Pick random items from a numbered list for surveys or testing.

Technical Guide

Random number generation uses Math.random() for standard use and offers unique mode using the Fisher-Yates shuffle algorithm. For unique numbers, an array of all possible values is created, shuffled, and the first N values are selected. This guarantees unbiased selection without replacement. The Fisher-Yates shuffle iterates backward through the array, swapping each element with a randomly chosen element from the remaining unshuffled portion, producing a uniformly random permutation in O(n) time. The tool validates that the requested quantity doesn't exceed the range size for unique mode.

Tips & Best Practices

  • 1
    Use unique mode for lottery-style draws where no number should repeat
  • 2
    For dice simulation, set range 1-6 with no unique constraint
  • 3
    The range is inclusive on both ends — min and max can both be generated
  • 4
    For negative ranges, set min to a negative number
  • 5
    Unique mode requires range size ≥ quantity — the tool will warn if not possible

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Frequently Asked Questions

Q Are min and max inclusive?
Yes, both the minimum and maximum values can appear in the results.
Q How does unique mode work?
It uses Fisher-Yates shuffle to randomly select numbers without replacement, guaranteeing no duplicates.
Q Can I generate negative numbers?
Yes, set the minimum value to a negative number to include negatives in the range.
Q Is there a limit on quantity?
Up to 10,000 numbers in standard mode. In unique mode, limited to the range size.
Q Are the numbers truly random?
They use Math.random() which provides good pseudorandom numbers suitable for most applications but not cryptographic use.

About This Tool

Random Number Generator is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.