How does the random picker work?

It uses JavaScript's Math.random() function to generate a random number between 0 and 1, then multiplies it by the number of items to select a random index. All items have an equal probability of being selected.

What's the difference between allowing duplicates and not?

When duplicates are allowed, an item can be selected multiple times, so the same result may appear more than once. When duplicates are not allowed, already selected items are excluded, ensuring all results are different.

Is the random picker fair?

Yes, Math.random() is a pseudo-random number generator that follows a uniform distribution, giving all items an equal probability of selection. However, it's not a perfect random number generator. For cryptographic security, crypto.getRandomValues() should be used.

Can I save the results?

Results are automatically saved to history with timestamps. However, refreshing the page will clear the history. For permanent storage, copy the results to a notepad or other application.

Where can I use the random picker?

It can be used in various situations such as team division, lottery draws, presentation order, menu selection, game participant selection, and prize winner selection. It's useful whenever fair random selection is needed.

Random Picker - Fair Random Selection Tool

What is Random Picker?

Random Picker is a tool that randomly selects from entered items. Using the computer's random number generator, all items have an equal probability of being selected, making it useful for all situations requiring fair draws or selections.

How to Use

Enter Items: Type one item per line in the text box
Set Pick Count: Enter how many items to select
Duplicate Option: Choose whether to allow duplicates with the checkbox
Execute Pick: Click the 'Pick' button to see results
Check History: Previous results are automatically saved to history

Random Picker Use Cases

1. Team Division

Use this to fairly divide teams at school, work, or clubs. Enter participant names and pick as many as the team size to automatically form teams.

Situation	Settings
Soccer (5 vs 5)	Enter 10 names → Pick 5 (no duplicates) → Rest are opposite team
Study Groups (4 teams)	Enter 20 names → Pick 5 each, 4 times (no duplicates)
Game Matching	Enter participants → Pick as many as game requires

2. Presentation Order

Enter presenters' names and pick them one by one to fairly determine order. With no duplicates, everyone is picked exactly once.

3. Lottery and Prize Winner Selection

Use this to pick winners from event participants. Enter participant numbers or names and pick as many winners as needed for a fair lottery.

4. Menu Selection

When you can't decide on lunch, enter menu candidates and pick one to overcome decision paralysis.

Lunch menu: Korean, Chinese, Japanese, Western → Pick 1
Dinner menu: Chicken, Pizza, Steak, Sushi → Pick 1
Snacks: Chips, Ice cream, Fruit, Bread → Pick 1

5. Game Participant Selection

Use this to randomly select participants for online or board games.

Allow Duplicates vs No Duplicates

Feature	Allow Duplicates	No Duplicates
Selection Method	Already selected items can be selected again	Once selected, items are excluded
Result	Same item can appear multiple times	Only different items are selected
Max Pick Count	Unlimited	Up to number of items
Use Examples	Dice rolls, lottery numbers	Team division, presentation order

How Random Picker Works

Random Picker uses JavaScript's Math.random() function. This function generates a floating-point random number between 0 (inclusive) and 1 (exclusive) following a uniform distribution.

Basic Algorithm

1. Generate random: Math.random() // e.g. 0.7234
2. Multiply by item count: 0.7234 × 10 = 7.234
3. Convert to integer: Math.floor(7.234) = 7
4. Select 7th item

Probability Distribution

With 10 items, each item has exactly 1/10 = 10% probability of being selected. Math.random() follows a uniform distribution, so all items have equal selection probability.

Quick Add Features

Numbers (1-100)

Automatically enters numbers from 1 to 100. Use for lottery number draws, seat assignments, number draws, etc.

Alphabet (A-Z)

Automatically enters uppercase letters A to Z (26 letters). Use for alphabet games, initial games, etc.

Practical Examples

Example 1: Soccer Team Division (10 people)

Enter 10 participant names, one per line
Pick count: 5
Check no duplicates
Click 'Pick' → 5 people for Team A, remaining 5 for Team B

Example 2: Presentation Order (5 people)

Enter 5 presenter names
Pick count: 1
Check no duplicates
Repeat 5 times → Determine order from 1st to 5th presenter

Example 3: Lunch Menu Decision

Enter menu candidates: Korean, Chinese, Japanese, Western, Fast food
Pick count: 1
Click 'Pick' → Today's lunch menu decided!

Frequently Asked Questions (FAQ)

Is it really fair? No manipulation?

Yes, it's completely fair. Math.random() is a random number generator built into the browser, and even developers cannot predict or manipulate the results. All calculations run only in your browser, and no data is sent to servers.

What if I have too many items?

There's no limit on item count, but entering over 1000 items can be tedious. If you need a number range, use the 'Quick Add - Numbers' feature, or copy-paste from Excel.

Can I save history permanently?

Current version clears history when you refresh the page. For permanent storage, copy results to notepad or Excel. Future updates will add local storage save functionality.

Can I use it on mobile?

Yes, it works normally on mobile browsers (Chrome, Safari, etc.). You can tap buttons and enter items with the keyboard.

What if the same item keeps appearing with duplicates allowed?

With duplicates allowed, the same item can theoretically be selected multiple times, but the probability is very low. When picking 5 from 10 items, the probability of all being the same is (1/10)^5 = 0.001%. If you keep getting the same results, try refreshing your browser.

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Random Picker

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