Utility

Random Number Generator

Generate random integers, decimals, dice rolls, coin flips, shuffled lists, and UUIDs. Powered by cryptographically secure randomness.

Quick Answer

A random number generator (RNG) produces unpredictable values within a specified range. Cryptographically secure RNGs (CSPRNGs) use the Web Crypto API and are suitable for passwords, tokens, and security-sensitive applications. A UUID v4 has 122 random bits, giving roughly 5.3 × 10^36 possible values — making collisions virtually impossible.

Random Integers

Generate random whole numbers within a range.

About This Tool

The Random Number Generator provides six modes of randomness in one tool, all powered by the Web Crypto API for cryptographically secure results. Whether you need a random number for a game, a UUID for a database, or a shuffled list for a raffle, this tool delivers fair, unpredictable results every time.

The Integer mode generates whole numbers within any range you specify. Set a minimum and maximum value, choose how many numbers you want, and generate. This is ideal for lottery-style draws, random selection from numbered lists, or any scenario where you need whole numbers.

The Decimal mode works similarly but produces numbers with fractional parts, useful for simulations, statistical sampling, and scientific applications where continuous random values are needed.

Dice, Coins, and More

The Dice Roller simulates the standard polyhedral dice used in tabletop role-playing games like Dungeons and Dragons: D4, D6, D8, D10, D12, and D20. Roll up to 20 dice at once, see each individual result, and get the total. The Coin Flip provides a simple heads-or-tails result with a satisfying animation.

The List Shuffler uses the Fisher-Yates algorithm to produce an unbiased random permutation of your items. Enter names, tasks, or any list of items, and shuffle them into a completely random order. The first item in the result is highlighted, making this perfect for picking winners from a list of raffle entries.

The UUID Generator creates version 4 UUIDs, which are 128-bit identifiers with an astronomically low collision probability. Developers use UUIDs as database keys, API tokens, file identifiers, and session IDs. Each UUID is formatted in the standard 8-4-4-4-12 hexadecimal pattern and can be copied with one click.

Frequently Asked Questions

Is this random number generator truly random?
This generator uses the Web Crypto API (crypto.getRandomValues), which provides cryptographically secure pseudo-random numbers. This is the strongest randomness available in a web browser and is suitable for security-sensitive applications, games, simulations, and statistical sampling.
What is a UUID and when would I use one?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hex digits in five groups (e.g., 550e8400-e29b-41d4-a716-446655440000). Version 4 UUIDs are randomly generated and have an extremely low probability of collision. They are commonly used as database primary keys, session tokens, file names, and API identifiers.
How does the dice roller work?
The dice roller simulates standard tabletop RPG dice: D4, D6, D8, D10, D12, and D20. Each roll generates a random number between 1 and the number of sides on the die. You can roll multiple dice at once (up to 20) and see individual results plus the total sum.
Can I use this for raffles and giveaways?
Yes. Enter your list of participants in the List Shuffler mode (one name per line) and shuffle to randomize the order. The first name in the shuffled list is the winner. For numbered entries, use the Integer mode to pick a random number in the entry range. Since this uses cryptographic randomness, the results are fair and unpredictable.
What is the difference between the Integer and Decimal modes?
Integer mode generates whole numbers within your specified range (e.g., 1 to 100). Decimal mode generates numbers with fractional parts (e.g., 0.384729). Use Integer mode for lottery-style picks, dice alternatives, and random selection. Use Decimal mode for simulations, statistical sampling, and any application requiring continuous random values.