Random Number Generator

Live draw board for inclusive integer tickets or half-open continuous samples, with replacement or unique ticket mode and a gate when the unique pool is too small.

Educational and recreational fairness only. Not for passwords, encryption keys, security tokens, or licensed gambling. Share links store settings only, not the drawn numbers.

By Ahmet C. Toplutaş·Site owner & editor · Math tools

Last updated May 21, 2026 · Reviewed May 21, 2026 · Planning estimates only - not tax, medical, or investment advice

Inclusive tickets vs half-open samples

Random draws serve two classroom jobs. Inclusive tickets pick whole numbers on [min, max] for dice, rosters, and lottery-style sets. Half-open samples pick continuous values on [min, max) for unit uniforms and simulation sketches.

This page's framing is a ticket vs sample choice, with replacement vs unique for tickets and a duplicate-risk gate when unique asks for more tickets than exist. It is not a password entropy board, not a quadratic nature gate, and not a P vs C twin.

Decision framing: “Do I need fair whole-number tickets, and must they be unique, or do I need a continuous sample on a half-open interval?”

Educational and recreational fairness only. Not for passwords, encryption keys, security tokens, or licensed gambling. For secret strings, use the password generator. See our disclaimers.

With replacement vs unique draw

With replacement, each ticket draw is independent; duplicates can appear (two dice both showing 4). Unique draw samples without replacement so each ticket appears at most once (a six-number lotto line from 1–49).

If unique count exceeds the inclusive ticket pool, the gate blocks the draw. Continuous samples stay on with-replacement only; “unique floats” is not a meaningful classroom mode here.

Fairness peel and entropy source

Integer tickets use rejection sampling on the browser CSPRNG when available so the inclusive range stays uniform. Continuous samples scale a unit float into [min, max). If CSPRNG is unavailable, the board falls back to Math.random and labels that honestly.

Fair draws for games are not the same job as generating passwords. Keep secrets on the password board.

Core relations

Inclusive tickets, half-open samples, and unique sampling.

Ticket: X = lo + floor(U × (hi − lo + 1)) with lo=⌈min⌉, hi=⌊max⌋ Sample: X = min + U × (max − min) U ∈ [0,1) Unique: partial Fisher–Yates on the ticket pool Pool size = hi − lo + 1

Example: min 1, max 6, count 2, with replacement → two independent dice. Same range, unique count 6 → a permutation of all faces.

Where this hands off

Sibling boards for counting, secrets, and algebra.

Permutations & combinations (how many ordered or unordered selections exist)
Password generator (CSPRNG secrets with entropy bands)
Percentage / quadratic
Terms: math glossary

Worked scenarios

Scenario A: Dice. Tickets 1–6, count 2, with replacement. Duplicates allowed.

Load Unique pick: 1–49, six unique tickets. Sorted line; pool size 49 must be ≥ 6.

Scenario B: Class roster. 1–30, five unique students. Tight-pool narrative may appear if you raise count near 30.

Scenario C: Unit sample. [0, 1), five decimals. Half-open continuous strip for simulation literacy.

Scenario D: Impossible unique. Ask for 10 unique tickets on 1–6. The gate blocks and explains the pool size.

Common mistakes

Using Math.floor(Math.random()×max)+1 patterns that bias uneven ranges.
Expecting unique floats on a continuous sample mode.
Sharing a URL and expecting the same numbers to reappear (settings only).
Using this board for passwords instead of the password generator.
Confusing “how many ways” (P/C) with “draw one outcome.”

How to use this board

Choose tickets or sample; for tickets pick replacement or unique.
Set min, max, and count (and decimals for samples).
Press Generate new draw; read the peel for pool size and entropy source.
Share writes settings only; typing does not rewrite the address bar.

When not to stop at this sketch

Stop here for fair classroom and game draws. Hand off for counting formulas or for secret generation. For regulated gambling or high-stakes cryptography, use purpose-built certified systems.

Counting: permutation & combination.
Secrets: password generator.

Frequently asked questions

How does this random number generator work?

Choose inclusive integer tickets [min, max] or a half-open continuous sample [min, max). Set how many numbers to draw and whether tickets allow replacement or must be unique. The board uses the browser CSPRNG when available (with rejection sampling for integers) and falls back to Math.random otherwise.

What is the difference between tickets and samples?

Tickets are inclusive integers: every whole number from ceil(min) to floor(max) can appear. Samples are continuous values on the half-open interval [min, max), useful for unit uniforms and Monte Carlo-style sketches.

What is with replacement vs unique draw?

With replacement, each ticket draw is independent so duplicates can appear. Unique draw samples without replacement (partial Fisher–Yates) so each ticket appears at most once. Unique mode is only for integer tickets.

Why can unique draw fail?

If you ask for more unique tickets than exist in the inclusive range, the draw is impossible. Widen the range or lower the count. A tight pool warning appears when you request a large share of the available tickets.

Is this safe for passwords or cryptography?

No. Even when the browser CSPRNG is used for fair draws, this page is educational and recreational. Do not use it for passwords, keys, tokens, or licensed gambling. Use the password generator for secret strings.

Are results reproducible from the URL?

No. Share links store range and mode settings only. Each Generate produces a new draw; typing does not rewrite the address bar until you share.

How is this different from permutations or the password generator?

Permutations count ordered selections. The password generator builds secret strings with entropy bands. This page draws numbers for fairness literacy: tickets vs samples and replacement vs unique.

Sources

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Inclusive tickets vs half-open samples

Decision framing: “Do I need fair whole-number tickets, and must they be unique, or do I need a continuous sample on a half-open interval?”

Educational and recreational fairness only. Not for passwords, encryption keys, security tokens, or licensed gambling. For secret strings, use the password generator. See our disclaimers.

With replacement vs unique draw

If unique count exceeds the inclusive ticket pool, the gate blocks the draw. Continuous samples stay on with-replacement only; “unique floats” is not a meaningful classroom mode here.

Fairness peel and entropy source

Fair draws for games are not the same job as generating passwords. Keep secrets on the password board.

Core relations

Inclusive tickets, half-open samples, and unique sampling.

Example: min 1, max 6, count 2, with replacement → two independent dice. Same range, unique count 6 → a permutation of all faces.

Worked scenarios

Scenario A: Dice. Tickets 1–6, count 2, with replacement. Duplicates allowed.

Load Unique pick: 1–49, six unique tickets. Sorted line; pool size 49 must be ≥ 6.

Scenario B: Class roster. 1–30, five unique students. Tight-pool narrative may appear if you raise count near 30.

Scenario C: Unit sample. [0, 1), five decimals. Half-open continuous strip for simulation literacy.

Scenario D: Impossible unique. Ask for 10 unique tickets on 1–6. The gate blocks and explains the pool size.

Common mistakes

Using Math.floor(Math.random()×max)+1 patterns that bias uneven ranges.
Expecting unique floats on a continuous sample mode.
Sharing a URL and expecting the same numbers to reappear (settings only).
Using this board for passwords instead of the password generator.
Confusing “how many ways” (P/C) with “draw one outcome.”

Frequently asked questions

How does this random number generator work?

What is the difference between tickets and samples?

What is with replacement vs unique draw?

Why can unique draw fail?

Is this safe for passwords or cryptography?

Are results reproducible from the URL?

No. Share links store range and mode settings only. Each Generate produces a new draw; typing does not rewrite the address bar until you share.

How is this different from permutations or the password generator?

Permutations count ordered selections. The password generator builds secret strings with entropy bands. This page draws numbers for fairness literacy: tickets vs samples and replacement vs unique.

Random Number Generator

Inclusive tickets vs half-open samples

With replacement vs unique draw

Fairness peel and entropy source

Core relations

Where this hands off

Worked scenarios

Common mistakes

How to use this board

When not to stop at this sketch

Frequently asked questions

How does this random number generator work?

What is the difference between tickets and samples?

What is with replacement vs unique draw?

Why can unique draw fail?

Is this safe for passwords or cryptography?

Are results reproducible from the URL?

How is this different from permutations or the password generator?

Sources

Inclusive tickets vs half-open samples

With replacement vs unique draw

Fairness peel and entropy source

Core relations

Where this hands off

Worked scenarios

Common mistakes

How to use this board

When not to stop at this sketch

Frequently asked questions

How does this random number generator work?

What is the difference between tickets and samples?

What is with replacement vs unique draw?

Why can unique draw fail?

Is this safe for passwords or cryptography?

Are results reproducible from the URL?

How is this different from permutations or the password generator?

Sources

What this number means

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