Random Number Generator

Generate single or multiple random numbers, unique sets, random picks from a list, dice rolls, and coin flips. Optional cryptographically-secure mode.

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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 make cryptographically strong passwords tool for dedicated password creation or the create MD5 or SHA-512 checksums tool for verifying file integrity.

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.

Does the Random Number Generator send my ranges, lists, or results to a server?

No. Random values are generated using the Web Crypto API’s crypto.getRandomValues, which is a cryptographically secure source of entropy that runs entirely in your browser. Your ranges, list items, dice rolls, and every generated value stay on your device — no network request is made.

Created by The Toobits Team · Engineering & Editorial

Toobits is built, tested, and maintained by a small independent engineering team. Every tool is written in TypeScript, runs entirely in the browser, and is reviewed against its source formulas before publication.

Editorial policy · Updated April 2026

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