Pseudorandom vs Cryptographic Randomness
Compare predictable generators with Web Crypto and learn when the difference matters. Review practical steps, examples, limits and privacy-aware checks before using the result.
Number Tools
Random Number Generator
Generate one or multiple random numbers within a range. Control decimals, duplicates, sorting and quantity.
🔒 Your list is processed locally in your browser. It is not uploaded unless you create a share link.
Input & settings
Result
Configure the tool, then run it.
Result history
- No results yet.
Quick answer
What does this tool do?
Random Number Generator creates integers or fixed-precision decimal values inside an inclusive range. It rejects impossible no-duplicate requests and can sort or export up to 1,000 generated values.
- Range limit
- -1,000,000,000 to 1,000,000,000
- Quantity
- 1 to 1,000
- Precision
- 0 to 8 decimal places
- Selection method
- Unbiased Web Crypto integer mapping
Why use this tool?
Random Number Generator creates integers or fixed-precision decimal values inside an inclusive range using unbiased browser-based random sampling. Set the minimum, maximum, quantity and decimal precision, then choose whether duplicate values are acceptable and whether the final list should be sorted. The tool validates impossible requests before generation, including reversed ranges, excessive quantities and no-duplicate requests that contain fewer available values than requested. Results include a localized generation time and can be copied or downloaded for exercises, testing data, numbered tasks and simple sampling. Decimal mode samples evenly spaced values at the selected precision rather than every possible real number. Generated values are not permanent identifiers or certified lottery numbers, and important decisions should include an independent review of the chosen range, settings and intended use.
How to use it
- Enter minimum and maximum values.
- Choose integer or decimal mode and quantity.
- Set duplicate and sorting preferences.
- Generate, copy or download the timestamped results.
Common use cases
- Create sample IDs
- Pick numbered tasks
- Generate practice values
Practical examples
- Generate five unique exercise numbers from 1 through 30.
- Create a reproducibility-free sample of decimal test values.
- Choose numbered tasks for a workshop.
How it works
Random values come from window.crypto.getRandomValues(). Lists are shuffled with an unbiased Fisher–Yates process. For a wheel, the result is chosen before the animation; for weighted entries, each positive weight defines its share of the total probability.
Limits to understand
- Generated values are not persistent identifiers.
- Decimal mode samples fixed increments rather than every real number.
- Do not use the tool as a regulated gambling system.
Privacy
Input and results stay inside this browser during normal use. Local saving is optional. If you select Create Share Link, the visible list and settings are uploaded under a hard-to-guess token and expire automatically.
Random Picker Tools · Editorial Policy · Updated:
Random Number Generator FAQ
Is my list uploaded?
No. Entries are processed in your browser unless you explicitly create a share link.
What kind of randomness is used?
The browser Web Crypto API supplies unbiased random values. Wheel animation only reveals a result chosen in advance.
Does it work on phones?
Yes. The controls, results and wheel adapt to current mobile browsers and keyboard navigation.
Can I reuse my settings?
Yes. Device storage can remember recent settings unless you turn off local list saving.
Is this suitable for a certified lottery?
No. It is a general-purpose classroom, work, event and decision tool, not a regulated drawing system.
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