About Randomizer
Random number generator with custom ranges, dice roller, coin flipper, and list picker. Generate truly random results for games, decisions, and drawings. Free and fast.
How to use
- Choose the type of random generation you need: random number within a range, random item from a list, coin flip, dice roll, random password, or random colour. Each mode is optimized for its specific use case with appropriate options.
- For random numbers, set the minimum and maximum values and how many numbers to generate. The generator uses cryptographically secure randomness for unbiased results. Generate integers or decimal numbers depending on your needs.
- For random list selection, enter your items (one per line or comma-separated) and specify how many to pick. The generator randomly selects items without repetition by default, or with repetition if enabled. Perfect for drawing contest winners, assigning tasks, or choosing team members.
- For dice and coin flips, select the number of dice (1-10) and the number of sides (standard 6-sided, or custom: 4, 8, 10, 12, 20 for tabletop gaming). The results show individual rolls and the total sum.
- View the results with a history of previous generations for comparison. The generator does not repeat or cycle through values — each result is independently random. Over many generations, the distribution approaches uniform randomness.
- Use the results for practical applications: raffle drawings, random team assignment, A/B testing decisions, random sampling for quality control, shuffling presentation order, or any situation where unbiased random selection is needed.
Frequently asked questions
Is this truly random?
Yes. This generator uses the Web Crypto API (window.crypto.getRandomValues), which provides cryptographically secure pseudorandom numbers. This is the same randomness source used by password managers and encryption software. It draws entropy from hardware-level sources (CPU thermal noise, mouse movement, keystroke timing) making the output unpredictable and uniformly distributed. Unlike Math.random() which uses a deterministic algorithm with a seed, crypto-grade randomness cannot be predicted or reproduced. For all practical purposes including contests, scientific sampling, and security applications, this output is truly random.
How do I generate a random number between 1 and 100?
Set the minimum to 1 and maximum to 100, select integer output, and click Generate. Each click produces a new independently random number. To generate multiple numbers at once, set the count to the number you need. For a lottery-style draw (unique numbers only), enable the no-duplicates option. This ensures each generated number appears exactly once, like drawing numbered balls from a bag. The generator handles ranges of any size from 1-10 to 1-1,000,000.
Can I use this for contest drawings?
Yes. Enter contestant names into the list selector and generate a random pick. The cryptographic randomness ensures every participant has an equal probability of being selected, satisfying fairness requirements for legitimate contests and raffles. For auditable drawings, use the timestamp and result together as documentation. For large-scale contests, generate multiple rounds of winners (first place, second place, etc.) using the no-repeat selection mode. Many small businesses and social media accounts use online random generators for giveaways and promotions.
How does a random dice roller work?
The dice roller generates a random integer between 1 and the number of sides on the die, with each face having an equal probability. For a standard 6-sided die, each number (1-6) has a 16.67% chance. For multiple dice, each die is rolled independently and the individual results are shown along with the sum. The probability distribution of the sum follows known patterns: for 2d6, the most common result is 7 (probability 16.67%) and the least common are 2 and 12 (probability 2.78% each). This roller supports standard RPG dice: d4, d6, d8, d10, d12, d20, and d100.
What is the difference between random and pseudorandom?
True randomness comes from physical processes (radioactive decay, atmospheric noise, quantum effects) that are fundamentally unpredictable. Pseudorandom number generators (PRNGs) use mathematical algorithms to produce sequences that appear random but are deterministic — given the same seed, they produce the same sequence. This generator uses a cryptographic PRNG (CSPRNG) that is seeded from hardware entropy sources, making it computationally indistinguishable from true randomness. For all real-world applications including gaming, statistics, security, and decision-making, CSPRNG output is equivalent to true randomness.
Can I generate random colours?
Yes. The colour generator produces random hex colour codes (#RRGGBB format) with optional constraints: completely random, limited to web-safe colours (216 colours that render consistently across all displays), limited to pastel tones (light, muted colours), or limited to a specific hue range. Each colour is displayed with its hex code, RGB values, and HSL values. Random colour generation is useful for design inspiration, data visualization colour assignment, generative art, and creating unique identifiers. Generate multiple colours at once to create random colour palettes.
How do I pick a random item from a list?
Enter your items in the text area (one per line or separated by commas) and click Generate. The picker randomly selects one item with equal probability for each entry. For multiple selections, set the pick count and choose whether duplicates are allowed. Without duplicates, it works like drawing names from a hat — once selected, an item cannot be picked again. With duplicates allowed, each draw is independent (like rolling dice). Common uses: picking a restaurant for dinner, assigning homework topics, choosing workout exercises, selecting random samples for testing, or drawing raffle winners.
Part of ToolFluency’s library of free online tools for Calculators. No account needed, no data leaves your device.