Random Number Generator
Generate cryptographically secure random numbers. Set a range, choose integers or decimals, request unique values, and produce several at once.
Options
Secure · localNumbers
About Random Number Generator
The Random Number Generator produces cryptographically secure random numbers within a range, as integers or decimals, optionally unique and in batches. It is for developers, researchers, and anyone needing dependable randomness.
Everyday random functions are predictable enough to matter in some uses. Drawing from the browser’s secure source gives stronger randomness locally, with no server involved.
Step by step
- Set the minimum and maximum of the range.
- Choose integers or decimals.
- Decide whether the numbers must be unique.
- Set how many to generate.
- Generate and copy the results.
What it offers
- Secure random number generation
- Integer or decimal output
- Unique-values option
- Batch generation
Where it helps
- Drawing winners for a giveaway fairly
- Generating sample data within a range
- Picking unique random selections without repeats
- Seeding a simulation or test
Tips for best results
- Keep the requested count of unique values within the size of the range.
- Use the unique option for draws where the same value must not repeat.
- For regulated draws, rely on a certified system rather than a browser tool.
Pitfalls to watch for
- Requesting more unique numbers than the range can supply, which is impossible to satisfy.
- Assuming decimals are evenly distributed to unlimited precision; they are bounded by representation.
- Using these for regulated gambling or lotteries, which require certified systems.
Why people use it
Strong randomness
From the secure random generator, not a basic shortcut.
Range control
Bound results to exactly what you need.
Unique option
Avoid repeats when required.
Private
Numbers are generated locally.
Common questions
This runs entirely in your browser
No file or text you enter here is uploaded. Encoding and decoding happen on your device using native browser APIs — close the tab and nothing remains on a server.