Random Number Generator

Generate cryptographically secure random numbers — single, batch, or pick from a list

Instant | 100% client-side
Single Number Space / Enter to re-roll
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Settings

Last Results

Quick Presets

Batch Settings

Results

Count
Min
Max
Mean
Median
Sum
Range
Std Dev
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Quick Presets

Pick from List

Picked Items

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Keyboard Shortcut

Press Space or Enter anywhere on the page to instantly re-roll a new number.

Quick Tips

  • Click the result area to quickly re-roll
  • Enable Auto-copy to copy each result automatically
  • Download batch results as a CSV file for spreadsheet use
  • Stats (mean, median, std dev) are computed on every generation
  • Paste comma-separated or one-per-line items — mix and match formats
  • Uses crypto.getRandomValues for cryptographic-grade randomness
  • Generate up to 1,000 numbers at once in Batch mode

100% Private

All random numbers are generated locally in your browser using the Web Crypto API. Nothing is sent to any server.

How Random Number Generation Works

Understanding the technology behind cryptographically secure random numbers

Random number generation is a fundamental operation in computing, used in everything from games and simulations to cryptography and scientific research. Our generator uses the Web Crypto API (crypto.getRandomValues), which provides cryptographically strong random values — the same standard used by password managers and security applications.

Unlike simple pseudo-random generators like Math.random(), the Web Crypto API draws entropy from hardware-level sources such as mouse movements, CPU timing jitter, and thermal noise, making the output unpredictable and suitable for security-sensitive use cases.

CSPRNG

Cryptographically Secure Pseudo-Random Number Generator ensures each number is statistically independent and impossible to predict from previous outputs.

Uniform Distribution

Every number in your specified range has an equal probability of being selected, ensuring fair and unbiased results for lotteries, games, and experiments.

Instant Results

Generate up to 1,000 random numbers in milliseconds. Results are computed locally with zero network latency, even when you are offline.

Common Uses for Random Numbers

From everyday decisions to professional applications

Lotteries & Raffles

Draw winning numbers for lotteries, sweepstakes, giveaways, and classroom raffles. Use the “no duplicates” option to guarantee unique picks.

Games & Dice Rolls

Simulate dice rolls, card draws, coin flips, or random game events. Use presets for common gaming scenarios like D6 or D20 dice.

Statistics & Sampling

Generate random samples for statistical analysis, A/B testing groups, or Monte Carlo simulations. Export results for further processing.

Education & Practice

Create random math problems, quiz questions, or exercise sets for students. Teachers can use bulk generation for worksheets and tests.

Frequently Asked Questions

Common questions about random number generation

This generator uses the Web Crypto API (crypto.getRandomValues), the same cryptographically secure random number source used by browsers for SSL/TLS connections and password managers. It produces uniformly distributed random numbers within your specified range, entirely in your browser.
They are cryptographically secure pseudo-random numbers (CSPRNG). The browser collects entropy from hardware sources (CPU jitter, mouse movement, etc.) to seed the generator. While technically pseudo-random, the output is statistically indistinguishable from true randomness and is suitable for security applications.
Yes. Switch to Batch mode and set the Quantity field to any value between 1 and 1,000. You can also enable "No duplicates" to ensure all generated numbers are unique, and "Sort results" to display them in ascending order.
Yes. Use the Decimal Places dropdown to choose 1–6 decimal places. For example, with min=0, max=1, and 6 decimals, you can generate values like 0.384729 — useful for probability simulations and statistical sampling.
Completely free, with no sign-up, no ads, and no usage limits. The tool runs 100% in your browser — we never see or store any of your generated numbers. It even works offline once the page has loaded.
You can use any integer range supported by JavaScript safe integers: from -9,007,199,254,740,991 to 9,007,199,254,740,991. For practical purposes, ranges like 1 to 1 billion work perfectly.
Pick from List lets you paste any set of items (words, names, options) separated by commas or newlines, then randomly selects N items from that list. It's perfect for choosing raffle winners, assigning tasks randomly, or picking discussion topics.