What is Random Number?
A random number generator is a tool that produces numbers without a predictable pattern, useful for simulations, games, sampling, and decision-making. This browser-based generator uses JavaScript's Web Crypto API to create cryptographically strong random integers between any two specified values — instantly, without uploading data to a server or requiring sign-up.
How Random Number works
This random number generator works entirely in your browser using the crypto.getRandomValues() API, which provides cryptographically strong entropy from your operating system's CSPRNG:
- You provide a minimum and maximum value (for example, 1 and 100).
- The tool calculates the range:
range = max - min + 1. - It generates raw random bytes using the Web Crypto API.
- The random bytes are converted to an integer and mapped to your range using rejection sampling to avoid bias.
- The result appears instantly in your browser — nothing is sent to a server.
Worked example:
Input: Minimum = 1, Maximum = 100
Range = 100 - 1 + 1 = 100 values
Output: 47 (a random integer between 1 and 100 inclusive)
Try again: Output: 82 (different random value; each generation is independent)
How to use
- Enter your content and choose any options.
- Your Random Number is generated instantly.
- Download or copy the result.
Common uses
- Picking a random winner or participant in a contest or raffle without bias.
- Rolling dice or spinning a wheel for games, board games, or role-playing campaigns.
- Selecting random samples from a population for statistical surveys or experiments.
- Shuffling or randomizing the order of items, questions on a quiz, or song playlists.
- Generating test data for software development, quality assurance, and stress testing.
- Making an unbiased decision by assigning random numbers to choices and picking one.