The 1–25 range
Twenty-five is a five-by-five grid: a bingo card, a seating plan, a sprint board, a wall of numbered envelopes. Small enough to take in at once, large enough that nobody can hold the pattern in their head.
Four percent each, no weighting, no memory of the last draw.
Raise the count and the numbers come back without repeats, which is how you draw a shortlist or fill part of a grid in one go.
- 1 to 25, both included
- 25 whole numbers
- 4%, exactly 1 in 25
- 1 to 10 numbers per draw
- None inside a multi-number draw
- Every draw gets a link that replays it
What a 1–25 draw is for
- Picking a square on a five-by-five bingo or picture card
- Choosing a desk, locker or seat from a numbered block of 25
- Drawing a door from a 25-day calendar
- Selecting a question from a 25-item quiz
- Sampling a 4 percent slice for a spot check
How the randomness works
Every tap calls crypto.getRandomValues, the browser's cryptographic generator, and asks it for one unsigned 32-bit value. That lands somewhere between 0 and 4,294,967,295, and it then has to be folded down to the 25 numbers in this range.
Folding it down with a plain remainder is where most generators go wrong, an error known as modulo bias. 25 does not divide 4,294,967,296 evenly: 21 values are left over at the top, and wrapping them around would make the first 21 numbers in the range fractionally likelier than the rest. This tool throws away any raw value at or above the last exact multiple of 25 and draws a fresh one instead. That is rejection sampling. It fires about 1 in 204,522,252 draws, and it is the difference between 4% exactly and 4% approximately.
Ask for more than one number and the tool keeps drawing until it holds that many distinct values, then sorts them ascending. Nothing is seeded, nothing is sent anywhere, and each draw is independent of the one before it. The roll history under the tool lives in your browser's local storage, where the clear button empties it. The daily lucky numbers elsewhere on this site work the opposite way on purpose: they use a seeded generator so the same date always returns the same set. How random is random sets the two side by side.
Twenty-five draws from 1–25 will not give you all 25 numbers, and the gap is wider than people expect. Tapping one at a time, the chance of collecting the full set in 25 tries is roughly one in six billion; the realistic outcome is around 16 distinct numbers and nine collisions. If you need every number exactly once, raise the count instead, because that draw excludes repeats by construction.
- crypto.getRandomValues, the browser's cryptographic generator
- One unsigned 32-bit value, sometimes more
- Rejection sampling onto 25 slots
- 21 of 4,294,967,296 raw values, redrawn
- No. These tools are never seeded
- Your browser. No server ever sees a draw
1–25 — frequently asked
Tap Generate with the range as it stands. Each number takes a twenty-fifth of the probability, which is a flat 4 percent.
Ten numbers at a time, with no repeats inside a draw. A five-by-five card needs three passes and a note of what you have already used, so for anything larger than ten a spreadsheet shuffle is less fiddly.
Independent draws collide. With 25 options, any two taps match one time in 25, and across a run of taps those matches pile up faster than intuition suggests. The multi-number draw is the fix when you need distinct results.