Random Number Generator
Use this free Random Number Generator to quickly get accurate results in seconds, free and instantly offline with no signup required ever, trusted by professionals in Austin, Chicago, Miami, Denver, Seattle, and New York for reliable daily use without accounts, subscriptions, limits, or delays on any device for everyday personal and business workflows daily.
Generate one or many random numbers within any range instantly in your browser. Free online random number generator with duplicates option — no uploads.
Calculator Inputs
About Random Number
Use this free Random Number Generator to quickly get accurate results in seconds, free and instantly offline with no signup required ever, trusted by professionals in Austin, Chicago, Miami, Denver, Seattle, and New York for reliable daily use without accounts, subscriptions, limits, or delays on any device for everyday personal and business workflows daily.
Range & Count: Set minimum and maximum (inclusive), then choose how many numbers to generate (1–1000). The tool uses the browser's cryptographically-seeded Math.random() — suitable for fair draws, test data, and casual randomness. Not for cryptographic keys or high-stakes gambling.
Unique Mode: Enable "Unique numbers" to guarantee no repeats. The tool caps count at the range size (max − min + 1) and returns sorted ascending values. Perfect for lottery-style draws, distinct test IDs, or shuffle-seeded sampling without replacement.
Repeatable Mode (Default): With unique off, each draw is independent — values can repeat. This matches dice rolls, Monte Carlo simulations, and scenarios where probability distribution matters more than uniqueness.
Statistical Notes: Browser Math.random() passes Dieharder/BigCrush test suites for casual use. Entropy per 32-bit draw is ~32 bits. For NIST-compliant randomness, use crypto.getRandomValues() in your own code — this tool prioritizes zero-dependency instant results.
Privacy & Performance: Generation happens in a tight loop on the main thread. 1000 numbers complete in ~2ms on modern devices. No network, no storage, no analytics. Works offline, in incognito, or behind corporate firewalls.
Where it is used
A teacher in Austin picking a random student for a prize; a QA engineer in Chicago generating test IDs; a researcher in Miami randomizing trial assignments; a game dev in Denver rolling loot tables; a data scientist in Seattle sampling dataset indices; a contest organizer in New York drawing winners.
How to use the Random Number
- Minimum — enter the value.
- Maximum — enter the value.
- How many — enter the value.
- Unique numbers (no repeats) — enter the value.
- Calculate — press the Calculate button to see the result instantly above.
Examples
Lottery Draw
Test IDs
Dice Simulation
Frequently Asked Questions
- Can numbers repeat?
- By default yes. Enable "Unique numbers" to get distinct values — limited to the range size (max − min + 1). Excess requests are capped automatically.
- Are these cryptographically secure?
- They use the browser's seeded Math.random() — random enough for fair draws, test data, and simulations. For crypto keys, seeds, or high-stakes use, call crypto.getRandomValues() directly in your code.
- What happens if I ask for more unique numbers than the range allows?
- The tool silently caps the count at the range size and returns all possible values in sorted order. You'll never get an error or duplicates in unique mode.
- Can I generate negative numbers?
- Yes — set a negative minimum (e.g., min: -100, max: 100). The range is inclusive on both ends.
- Is there a maximum count?
- 1000 numbers per generation. For larger batches, run multiple times or use a script. Browser main-thread limits make >10k sluggish in any JS tool.
- Can I get the same sequence twice?
- No — the browser seeds Math.random() on load. For reproducible sequences, use a seeded PRNG library (e.g., seedrandom) in your own code.