Generate random numbers, flip coins, roll dice, and pick cards. Fast, free, and fair.
The random number generator uses JavaScript's built-in Math.random() function, which produces pseudo-random numbers using an algorithm that is suitable for everyday applications. When you allow duplicates, each number is independently generated. When duplicates are disabled, the tool creates a pool of all possible numbers in your range, then randomly selects from that pool without replacement.
The coin flipper, dice roller, and card picker all use the same underlying random function. A coin flip generates a random number between 0 and 1, with less than 0.5 being Heads. Dice rolls generate a number from 1-6. Card picks randomly select from all 52 standard playing cards (4 suits of 13 values).
| Event | Possible Outcomes | Probability | Percentage |
|---|---|---|---|
| Coin Flip — Heads | 2 (Heads, Tails) | 1 in 2 | 50% |
| Coin Flip — Tails | 2 | 1 in 2 | 50% |
| Single Die — Any specific number | 6 | 1 in 6 | 16.67% |
| Two Dice — Rolling a 7 | 36 combinations | 6 in 36 | 16.67% |
| Two Dice — Rolling a 12 | 36 | 1 in 36 | 2.78% |
| Card — Specific suit | 4 suits | 1 in 4 | 25% |
| Card — Specific rank | 13 ranks | 1 in 13 | 7.69% |
| Card — Specific card | 52 cards | 1 in 52 | 1.92% |
| Royal Flush (Poker) | 2,598,960 hands | 4 in 2,598,960 | 0.000154% |
| Use Case | Typical Range | Quantity Needed |
|---|---|---|
| Lottery Numbers | 1–49 or 1–69 | 5–6 unique numbers |
| Raffle Winner | 1–total entries | 1 number |
| Dice Roll | 1–6 | 1–2 numbers |
| Card Draw | 1–52 | 1–5 cards |
| Random Password Char | 1–95 (printable ASCII) | 12–24 characters |
| Statistical Sampling | 1–population size | Varies (sample size) |
| Random Groups / Teams | 1–group count | 1 per person |
| Simulation Seeds | 1–2,147,483,647 | 1 seed value |
| Monte Carlo Simulation | 0.0–1.0 | Thousands to millions |
| Sum | Possible Combinations | Ways to Roll | Probability |
|---|---|---|---|
| 2 | (1,1) | 1 way | 2.78% |
| 3 | (1,2), (2,1) | 2 ways | 5.56% |
| 4 | (1,3), (2,2), (3,1) | 3 ways | 8.33% |
| 5 | (1,4), (2,3), (3,2), (4,1) | 4 ways | 11.11% |
| 6 | (1,5), (2,4), (3,3), (4,2), (5,1) | 5 ways | 13.89% |
| 7 | (1,6), (2,5), (3,4), (4,3), (5,2), (6,1) | 6 ways | 16.67% |
| 8 | (2,6), (3,5), (4,4), (5,3), (6,2) | 5 ways | 13.89% |
| 9 | (3,6), (4,5), (5,4), (6,3) | 4 ways | 11.11% |
| 10 | (4,6), (5,5), (6,4) | 3 ways | 8.33% |
| 11 | (5,6), (6,5) | 2 ways | 5.56% |
| 12 | (6,6) | 1 way | 2.78% |
Total combinations: 36. The most likely sum is 7 (6 out of 36 = 16.67%). Least likely: 2 and 12 (1 out of 36 each).
This tool uses the browser's built-in Math.random() function which generates pseudo-random numbers. For most everyday uses like picking winners, rolling dice, or generating lottery numbers, the randomness is more than sufficient.
Yes. Uncheck the "Allow duplicates" checkbox to generate a set of unique numbers within your specified range. Note that the quantity cannot exceed the total numbers in the range (e.g., you can only get 100 unique numbers from 1-100).
You can use any integer range. The tool supports negative numbers and very large ranges. The only limit is that you can generate up to 1,000 numbers at once in a single batch.
The coin flipper generates a random number between 0 and 1. If the result is less than 0.5, it returns "Heads"; otherwise, it returns "Tails". This gives a fair 50/50 probability for each outcome.
Yes. Set the minimum and maximum to match your lottery's number range, set the quantity to however many numbers you need, and uncheck "Allow duplicates" to get unique picks. The tool can also roll dice and pick random playing cards.
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