What is a random number picker?
A random number picker is a tool that chooses one or more numbers from a range you set, with every candidate equally likely. You give it a minimum and a maximum; it returns numbers nobody could have predicted.
This one runs in your browser. Set the range, choose how many numbers you need, decide whether the same number may appear twice, and press Pick. Optional filters restrict the draw to even, odd or prime numbers, to a fixed step such as every 5, or to decimals with up to three places.
Nothing you enter is sent to a server: the draw happens on your device, and the history stays in your browser until you clear it.
How the random number generation works
Each pick comes from crypto.getRandomValues(), the same cryptographically secure generator browsers use for encryption keys. The picker maps the range onto a list of candidates and draws an index, so a range of a billion numbers costs no more than a range of ten.
- Count the candidates. 1–100 has 100. Even numbers from 1–100 have 50. Steps of 5 from 5–30 have 6. Decimals to one place between 0 and 1 have 11.
- Draw an index without bias. A 32-bit random value is accepted only when it falls inside a multiple of the candidate count, then reduced. This rejection sampling removes the small bias a plain modulo would add.
- Map it back to a number. Whole numbers, steps and decimals are all points on a grid, so the index becomes the value with one multiplication; primes are listed first with a sieve.
- Repeat, with or without replacement. With repeats allowed each draw is independent. With unique numbers the picker shuffles or rejects duplicates so no candidate is used twice.
Secure RNG versus Math.random()
| Property | crypto.getRandomValues (this tool) | Math.random() |
|---|---|---|
| Predictable from earlier values | No | Yes, in principle — it is a fast pseudo-random sequence |
| Bias on ranges that do not divide 2³² | Removed by rejection sampling | Present with the usual floor-and-multiply approach |
| Good enough for | Draws people care about: winners, seats, tickets | Cosmetic effects, animation jitter |
What you can use it for
- Pick a winner. Number each participant and draw a ticket, fair and visible. Random name picker →
- Bingo or board games. Uncheck “Allow repeats” to pull a unique set of numbers with no duplicates.
- Classroom random pick. Roll a number to call on a row, page, or problem set.
- Dice or coin replacement. 1–6 for a die, 1–2 for a coin flip, 1–100 for a percentile roll. Roll a die → Coin flipper →
- Bingo-style draws. Set the range to 1–75, turn repeats off and pick as many as you need; turn on Sort results to read them in order.
- Maths and statistics practice. Draw 50 numbers with repeats and compare the summary line with what you expected; switch to decimals or primes for variety. Probability Simulator →
Unique numbers or repeats: which to choose
The ‘Allow repeats’ switch decides whether one draw can show the same number twice. Both are fair; they answer different questions.
| You want | Setting | Example |
|---|---|---|
| Several different winners, seats or bingo balls | Repeats off (unique) | 5 unique from 1–50 → 12, 3, 41, 27, 8 |
| Independent rolls, like dice or a coin | Repeats on | 4 from 1–6 → 3, 3, 6, 1 |
| Every candidate exactly once, in random order | Repeats off, count equal to the range | 10 unique from 1–10 → a shuffle |
With repeats off the count is capped at the number of candidates: ask for 20 unique numbers from 1–10 and you get 10.
Picking several numbers at once
- Set the range, then ‘How many to pick’ — up to 500.
- Turn repeats off if each number must be different; leave them on for independent rolls.
- Turn on Sort results under More options when order helps, for example when reading the numbers out loud.
- After the draw, use Copy for the numbers, Share for an image, or Export in the history for a text file of every draw this session.
Tips for a fair draw
- Number the entries before you draw, and show the numbering to everyone. A random number is only fair if people agree what it refers to.
- Give the pick a title (‘Raffle ticket’, ‘Presenter’). It is saved with the result and printed on the shared image, so the number keeps its meaning.
- Draw once. Re-rolling until you like the answer is the one way to make a fair picker unfair.
- For a public giveaway where entrants must be able to check the result themselves, use the verifiable draw instead — it publishes a commitment before the entries close. Verify a Draw →
- Prefer the wheel when the audience should see the pick happen; prefer numbers when the list is long or private. SpinOfLuck spin wheel →
Frequently asked questions
- Is the number picker truly random?
- Yes. Picks are generated with crypto.getRandomValues(), the browser’s cryptographically secure random function, and we use rejection sampling to avoid the modulo bias you’d get from a naive Math.random() approach. Each pick is independent and unpredictable, even on tiny ranges like 1–10.
- What range can I pick from?
- Any whole-number range, positive or negative, as long as the span (max − min + 1) fits within a billion possible values. Min must be less than or equal to max.
- How do I draw multiple numbers at once?
- Set ‘How many to pick’ to the number you want, up to 500. They are revealed together at the end of one roll, and a summary shows the lowest, highest, sum, average and median.
- Can the same number repeat across picks?
- Yes. By default repeats are allowed, so each pick is independent. Uncheck ‘Allow repeats’ to draw a unique set, so no number comes up twice in the same draw — handy for bingo, team numbers, or picking several winners at once.
- Does this work offline?
- After the page has loaded once, the number picker runs entirely in your browser, with no server calls during a draw.
- Can I generate decimal numbers?
- Yes. Under More options set Decimal places to 1, 2 or 3. The range is then a grid at that precision, so 0 to 1 with one place has eleven candidates: 0, 0.1 … 1.
- Can I generate negative numbers?
- Yes. Type a negative minimum, for example −20 to 20. Even and odd filters work across zero too.
- Can I pick only even, odd or prime numbers?
- Yes. Choose the filter under More options. Primes are listed with a sieve, so the range for primes is limited to two million numbers; even, odd and step have no such limit.
- Does the tool store my data?
- The draw runs in your browser and the recent picks list is kept in your browser’s storage only. Nothing you type is sent to a server. If you sign in, your settings and results can sync to your own account so they follow you across devices.
- Can I share or copy the result?
- Copy puts the numbers on the clipboard; Share makes an image card you can send anywhere; Export in the history saves every draw of the session as a text file.
- Does it work on my phone?
- Yes. The picker is built for touch: large targets, a numeric keyboard for the range, and an instant mode for devices that ask for less motion.
- Is it free?
- Yes, with no signup, no limits on draws and no ads in the way. It is made for games, classrooms and friendly draws, not gambling.
More random tools
Same fair randomness, different shape. All free, no signup.
- SpinOfLuck spin wheel →Type names or options and spin for a winner.
- Random name picker →Paste a list of names and draw one at random.
- Roll a die →One die or several, any number of sides.
- Coin flipper →Heads or tails, one flip or a streak.
- Yes / No spinner →A quick, fair answer to a yes-or-no question.
- Team picker →Split a list into random, balanced teams.