Random Number Generator
Free online random number generator. Generate single or multiple random numbers, unique sets, random from a list, dice rolls, and coin flips. Cryptographically secure option included. No signup.
How to Use the Random Number Generator
Choose a mode from the tabs: Number for a single value in a range, Multiple for a batch of numbers, Dice for tabletop game rolls, Coin for fair coin flips, List to randomly select from your own options, Sequence for shuffled ranges, and Secure for cryptographically strong values. Adjust the controls, click Generate, and press Space to generate again instantly. All results are logged in the history panel below.
About This Tool
A multi-mode random number and selection tool built with native browser APIs. Standard modes use Math.random() for fast, statistically uniform generation suitable for games, simulations, and everyday decisions. The Secure mode uses crypto.getRandomValues() — a cryptographically secure pseudo-random number generator (CSPRNG) — with rejection sampling to eliminate modulo bias. Features include dice rolling with D&D presets (including 4d6 drop lowest), animated coin flips, random list picking with elimination mode, sequence shuffling, UUID v4 generation, and random password creation with entropy calculation. Zero external libraries. Pair with the Password Generator for dedicated password creation or the Hash Generator for checksums.
Quick Reference Table
| Mode | Best For |
|---|---|
| Number | Single random value in a range |
| Multiple | Batch of numbers with optional uniqueness |
| Dice | Tabletop RPG polyhedral dice rolls |
| Coin | Fair 50/50 coin flips |
| List | Random selection from custom options |
| Sequence | Shuffled ranges and lottery numbers |
| Secure | Crypto-safe tokens, UUIDs, passwords |
Frequently Asked Questions
Is Math.random() truly random?
Math.random() uses a pseudo-random number generator — a deterministic algorithm that produces sequences that appear statistically random but are not cryptographically secure. For everyday uses like games, simulations, and random selections, it is entirely adequate. For security tokens and passwords, use the Secure mode which relies on crypto.getRandomValues().
What is 4d6 drop lowest?
This is the standard method for generating character ability scores in Dungeons & Dragons. Roll four six-sided dice (4d6), discard the lowest result, and sum the remaining three. The expected value is higher than a straight 3d6 roll, producing more competent characters.
What is a UUID and when should I use one?
A UUID (Universally Unique Identifier) is a 128-bit value formatted as 8-4-4-4-12 hexadecimal characters. UUID v4 is randomly generated. Use UUIDs as unique keys for database records, file names, session tokens, and anywhere a collision-resistant identifier is needed.
How many random items can I pick from a list?
You can add any number of items to the list and pick any count up to the total number of items when duplicates are disabled. For very large lists, the shuffle-based selection algorithm remains fast.