About Random Nr
A set of fast random generators that run entirely in your browser, with no accounts, no uploads and no clutter around the tool.
How randomness works here
Every tool draws from the Web Crypto random source your browser provides, which is seeded by the operating system from real world entropy. Values are mapped into your chosen range with rejection sampling, so no number is slightly more likely than another because of rounding.
That is a pseudo random generator with a strong seed rather than a hardware device reading atmospheric noise. For draws, games, sampling and teaching it behaves the way a fair physical device would. If you need repeatable output instead, the seeded generator gives the same sequence for the same seed.
Who uses Random Nr, and for what
The same handful of generators cover a surprising range of jobs. Here is who reaches for Random Nr most, and the tools that fit each one.
Students and learners
Practise arithmetic, explore number patterns and check your own working. Start with the maths question generator, the prime number list or the Fibonacci generator.
Teachers and classrooms
Call on students fairly, split a class into teams and print fresh worksheets. Use the classroom number picker, the group assignment generator and the number picker wheel.
Developers and testers
Seed databases and fill forms with believable but inert test data. Reach for the random number list generator, the IBAN generator and the phone number generator.
Gamers and tabletop players
Roll any dice, deal cards and set drop rates without hunting for a physical set. Try the dice roller, the playing card generator and the weighted generator.
Event organisers
Run raffles and giveaways that everyone can see is fair. Number the tickets with the ticket generator, then draw winners with the raffle generator or the picker wheel.
Researchers and analysts
Draw unbiased samples and model outcomes for a study or a report. Use the sample generator, the normal distribution generator and the odds simulator.
Everyday privacy
Set a code you can actually rely on, right in the browser. Generate one with the PIN code generator, the lock combination generator or the secure random generator.
Lottery players
Get an instant quick pick built to each game's exact rules. Try the lottery number generator, Powerball or EuroMillions.
Not sure where to begin? The random number generator is the one most people open first, and the full list of tools groups every generator by type. If you would rather see how the draws stay fair before you trust them, the how randomness works section above walks through it.
Many jobs cross over: a teacher runs a classroom raffle, a developer needs a fair sample, a gamer wants a repeatable seed. The number randomizer and the no repeats generator sit behind a lot of these, so they are worth a look whatever brought you here.
Design principles
- The tool comes first, above the fold, working on the first load
- Plain HTML pages that load fast on any connection
- One page per job so each has a clear title, purpose and result
- Explanations below the tool, never in front of it
- Every result copyable and downloadable as CSV
Privacy
Nothing you type is sent to a server. Ranges, lists and results stay on your device, which also means the tools keep working if your connection drops after the page has loaded.
Contact
Spotted a generator that is missing, or something that could work better? Suggestions are always welcome, and plenty of the tools here started as exactly that.
Credits
The dice and coin artwork comes from game-icons.net by Delapouite, Skoll and Lorc, used under the CC BY 3.0 licence. Barcodes are drawn with the JsBarcode library under the MIT licence. Both are bundled with the site, so nothing loads from another server.
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