Random Number Generator

Free online random number generator that creates random integers or decimals within any range, with options for count, duplicates, and sorting.

Result

What Is This Tool?

This free online random number generator produces random integers or decimals within any range you choose, right in your browser. Set a lower and upper limit and generate a single number instantly, or open the advanced options to create many numbers at once, control how many, allow or prevent duplicates, choose the sort order, and set the decimal precision. Results can be copied to the clipboard or regenerated with one click. It works on any device with no sign-up, installation, or download required.

How to Use This Tool?

  • Enter a lower limit and an upper limit for the range.
  • Click Generate to produce a random number instantly — pressing Enter works too.
  • Open Advanced options to set how many numbers, the type (integer or decimal), the sort order, and whether duplicates are allowed.
  • Use the copy button to copy your results, or regenerate to get a new set with the same settings.

Key Features

  • Generates random integers or decimals within any lower and upper limit you set
  • Creates a single number by default, or many at once through the advanced options
  • Offers control over count, duplicate values, sort order, and decimal precision
  • Includes one-click copy-to-clipboard and regenerate buttons, plus clear input validation
  • Runs entirely in the browser on any device — no sign-up, installation, or download required

Examples

  • Roll a die: set the range to 1 and 6 and generate a single integer.
  • Pick lottery numbers: set the range to 1 and 49, choose how many, and turn duplicates off.
  • Generate a random decimal between 0 and 1 with 2 decimal places for a probability value.
  • Draw a shuffled order: generate many integers in a range with duplicates off and sort ascending.

Common Use Cases

  • Games and raffles needing dice rolls, draws, or random picks
  • Teachers and students running probability and statistics demonstrations
  • Developers and testers needing quick sample data or random inputs
  • Choosing winners fairly from a numbered list of entries
  • Anyone needing a fast, unbiased random pick without installing an app

Tips & Best Practices

  • Turn off duplicates when every result must be unique, such as a raffle draw.
  • Use the count field in advanced options to generate a whole set in one step instead of clicking repeatedly.
  • Set the decimal places to match the precision your task actually needs.
  • Sort results ascending or descending to make long lists easier to scan.
  • Use the regenerate button to quickly reshuffle without re-entering your settings.

Limitations

  • Uses the browser's built-in pseudo-random generator (Math.random), which is fine for everyday use but not suitable for cryptography, security, or gambling systems.
  • Generates up to 10,000 numbers at a time to keep the page responsive.
  • Whole numbers are accurate within the standard JavaScript safe-integer range (about 15–16 digits), not arbitrary thousands of digits.
  • The copy-to-clipboard button requires a secure (HTTPS) connection to work.

Frequently Asked Questions

Is this random number generator free?
Yes. It runs entirely in your browser and needs no sign-up, installation, or download, and it works on desktop, tablet, and phone.
Are the numbers truly random?
They are pseudo-random, produced by the browser's Math.random function. This is suitable for games, draws, and sampling, but not for cryptographic or security-sensitive purposes.
How do I generate numbers without repeats?
Open Advanced options and turn off 'Allow duplicate values.' If you request more numbers than there are unique values in the range, the tool will tell you.
Can I generate decimal numbers?
Yes. In Advanced options, set the type to Decimal and choose how many decimal places you want.

Key Terminology

Random Number
A number chosen from a range with no predictable pattern, so each outcome is equally likely.
Pseudo-random
Numbers produced by an algorithm that approximate true randomness but are ultimately deterministic.
Range
The span between the lower and upper limits within which numbers are generated.
Duplicate
A value that appears more than once in a set of results; it can be allowed or prevented.
Precision
The number of decimal places used when generating decimal values.

Quick Knowledge Check

Which setting ensures the same number is never repeated in your results?
What kind of randomness does this tool use?
Where do you find the option to generate many numbers at once?