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Roulette, Name Picker & Amidakuji

Spin a wheel to pick a winner, draw names, split a group into teams, make an Amidakuji ladder, or roll dice and random numbers, all in your browser. Results come from the browser’s cryptographic random source, and the names you enter are never sent anywhere.

On-device・No uploadMobile friendlyWorks offline

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

Items (names or choices)

One per line. Blank lines are ignored.

Example: Apple*3 has three times the chance of an item written without a weight. Weights are whole numbers from 1 to 100.

Items are saved only in this browser. They are never put in the URL.

Roulette

Press “Spin” to pick one item at random.

A removed item is also taken off the list. To bring it back, type it into the list again.

The spin takes about 4 seconds. If “reduce motion” is on, the spin is skipped and the result is shown at once.

History (cleared when you leave the page)

No results yet.

How to use

  1. Items, one per lineone per line

    Enter the items

  2. Pick one winner

    Spin to pick a winner

  3. Remove the winner, go onthree left

    Remove it and keep going

Pick a winner, then remove it and keep going

  1. Open “Roulette”. Six sample items are already in the list, so you can press “Spin the wheel” at once. Type your own items, one per line.

  2. For weights, turn on “Use weights” and write “*3” at the end of a line. The 3 means that item has three times the chance of an item without a weight.

  3. When the wheel stops, the winner appears in large type. Turn on “Remove the winner and keep going” to take the winner off the list and draw again.

  4. In “Draw & teams”, enter how many to pick or how many teams to split into. In “Amidakuji”, enter one result per name, press “Make the ladder”, then choose a name and press “Trace one line” to see its path.

  5. In “Dice, coin & numbers”, choose the number of sides, the count or the range and press the button. Each result is also kept in the history below (until you leave the page).

What it does

Weighted wheel

Give each item a whole-number weight from 1 to 100. The winner is chosen with a probability proportional to its weight, and the wheel stops inside that item. A mode removes the winner and keeps going.

Unbiased randomness

Every draw (wheel, name picking, teams, Amidakuji, dice and numbers) takes its values from crypto.getRandomValues, the browser’s cryptographic random source. Values in the uneven part of the range are discarded and drawn again, so no value is favoured.

An Amidakuji where everyone gets a different result

Bars are placed so that no two bars in one row touch. Each row is therefore a set of swaps between neighbouring lanes, and every starting point reaches a different result. You can follow one path step by step, and see all answers in a table.

Teams that differ by at most one person

The group is split so that every team differs in size from every other by at most one person. Random draws decide only who goes into which team.

Your list stays on this device

The item list and the Amidakuji results are saved in this browser only. They are never put in the URL, so a shared link cannot reveal names. Full screen, an optional sound, keyboard use and spoken results (live announcements) are supported.

Use cases

  • Pick whose turn it is or where to eat lunch with a quick spin
  • Choose a presentation order or a raffle winner from a list of names
  • Split workshop participants into teams whose sizes differ by at most one
  • Show a full-screen wheel at an event or on a stream
  • Assign prizes or roles with an Amidakuji, so that every person gets a different result

Supported formats

Wheel & draw

1–200 items (up to 200 characters each)Weights: whole numbers 1–100 (optional)

Amidakuji & random

Amidakuji: 2–12 peopleDice: 4, 6, 8, 10, 12, 20 or 100 sides (up to 20 at once)Numbers: −1 billion to 1 billion (up to 1,000 at once)

Capability matrix

FeatureSupportNotes
Wheel (weighted, remove the winner and continue)SupportedThe spin takes about 4 seconds
Name draw without repeatsSupportedWeights are not used
Teams (sizes differ by at most one)SupportedUp to the number of items
Amidakuji (2–12 people)SupportedBars are drawn automatically
Drawing the bars by handNot supportedUse “Draw new bars” to redraw
Dice, coin and random numbersSupportedNo-repeat option for numbers
Reproducing a result later (random seed)Not supportedResults come from cryptographic randomness and cannot be reproduced
Shareable link with the resultsNot supportedNames are never put in the URL
Saving the list in this browserSupportedNot carried over to other devices or browsers
Full-screen displayPartialOnly where the browser supports it
Offline useSupportedWorks without a connection once loaded

Limits & notes

  • Up to 200 items, each up to 200 characters. Weights are whole numbers from 1 to 100.
  • Amidakuji works with 2 to 12 people. Enter as many results as there are names.
  • Dice come in 4, 6, 8, 10, 12, 20 or 100 sides; roll up to 20 at once. Coins: up to 100 flips at once.
  • Random numbers range from −1 billion to 1 billion, up to 1,000 at once.
  • If the system setting “reduce motion” is on, the spin is skipped and the result is shown at once.
  • Works on phones (checked at 390 px wide). A larger screen is easier to see from a distance for a full-screen wheel.

Privacy & safety

The item list and the Amidakuji results are saved only in your browser (localStorage). Nothing is sent to a server, put in the URL or recorded in analytics. The result history is cleared when you leave the page.

FAQ

Is the wheel really unbiased?
Yes. Each winner is chosen from values taken from crypto.getRandomValues, the browser’s cryptographic random source. Values in the uneven part of the range are discarded and drawn again, so no item is favoured. With weights, each item’s chance is proportional to its weight.
Does every person get a different result in Amidakuji?
Yes. Bars are placed so that no two bars in one row touch, which makes each row a swap between neighbouring lanes. Such swaps always pair each start with exactly one finish, so no two people reach the same result.
Are the names I type sent anywhere?
No. The list and the Amidakuji results are only saved in this browser. They are not put in the URL, sent to a server or included in analytics.
How do I show the wheel full screen?
Press “Full screen” and only the wheel is shown large. If the browser does not support full-screen display, the button does nothing. Press Esc to return.
Are the teams the same size?
Yes. Any two teams differ by at most one person. Leftover people are placed one per team from the first team onward, and random draws decide only who joins which team.

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