Random Number Generator
Generate random numbers with custom range.
Online random number generator: cryptographically secure values
Generating random numbers is a common need in multiple fields: from raffles and board games to statistical simulations, software testing, and cryptographic applications. Our generator uses the browser's crypto.getRandomValues API, which produces cryptographically secure values.
The tool lets you define a minimum and maximum range, choose how many numbers to generate (up to 100 at a time), decide if duplicates are allowed, and if you want results sorted. When you disable duplicates, the generator uses the Fisher-Yates algorithm.
All processing is done locally in your browser, without sending data to any server. Generated numbers can be easily copied to the clipboard. This tool is ideal for raffles, lotteries, random task assignment, and test data generation.
Frequently asked questions
Are the generated numbers truly random?
Yes. We use the browser's crypto.getRandomValues function, which accesses an operating system entropy source to generate cryptographically secure values. This is significantly more robust than Math.random(), which uses a predictable pseudorandom generator. The numbers are suitable even for security applications.
Can I use this for raffles or drawings?
Yes, this tool is perfect for informal raffles. Set the range according to the number of participants, disable duplicates to avoid repetitions, and generate the number of winners you need. The results are unbiased thanks to the browser's cryptographic API.
What is the difference between crypto.getRandomValues and Math.random?
Math.random() uses a deterministic algorithm that, knowing the initial seed, allows predicting all future values. crypto.getRandomValues() obtains bytes from an operating system entropy source (hardware noise, CPU timing, etc.), producing unpredictable values. For raffles, games, and security, crypto.getRandomValues() is always recommended.
Want to learn more? Read our complete guide →