🎲 Random Number Generator 1 to 19

What is the Random Number Generator 1-19?

A random number generator set to 1 and 19 restricts every pick to one of 19 whole numbers, with 1 and 19 both included as valid results. This exact span is genuinely useful whenever something you are working with comes in a set of 19, for example a shortlist of 19 candidates, a book with 19 chapters, or a form numbered 1 to 19. It is a narrower range than the more familiar 1 to 20 (a standard 20 sided die), so this preset is not the right choice if you actually need a d20 roll; change the Maximum field to 20 for that instead.

Fairness here comes from the Web Crypto API rather than a simple formula-based generator. The tool reads a 32-bit value from crypto.getRandomValues and applies rejection sampling: any raw value that would fall in the small leftover slice that does not divide evenly by 19 is discarded and a fresh value is drawn instead. This removes the modulo bias that affects naive random number code, so all 19 values, from 1 through 19, carry an identical 1 in 19 probability on each independent pick.

The Allow duplicates checkbox controls whether picks are independent or drawn from a shrinking pool. With duplicates allowed, each number is chosen on its own, so the same value can turn up twice in a row, in the same way a die roll can repeat. With duplicates switched off, the tool performs a partial Fisher-Yates shuffle over the 19 possible values, removing each number from the pool once it is drawn; this caps how many unique numbers you can request at 19, since that is the entire size of the range.

Because the range only spans 19 values, results start repeating faster than with a wider range like 1 to 100, especially once you have drawn many unique numbers and the pool is running low. Use the Sort results ascending option if you want a multi-number result listed in order rather than in the order it was drawn, which is often easier to read out for a raffle or a turn-order list.

When to use it

• Picking a random winner from a list, group, or raffle of up to 19 entries or names.
• Choosing a random question, page, or item number from a set of 19, such as a 19 question quiz or a 19 track playlist.
• Assigning random turn order or team position among up to 19 players.
• Running a simple number-guessing game where the answer is a whole number from 1 to 19.
• Selecting a random sample row or ticket number when a dataset or batch has exactly 19 entries.

How to use the Random Number Generator 1-19

1. The Minimum and Maximum fields are already set to 1 and 19, so a result is ready as soon as the page loads.
2. Adjust "How many" if you want more than one number at a time.
3. Leave Allow duplicates ticked for independent picks, or untick it for unique numbers with no repeats.
4. Tick Sort results ascending if you want multiple numbers listed in order.
5. Click Generate for a fresh pick, then Copy to place the result on your clipboard.

Formula & method

Worked examples

Nearby ranges and what they suit

How the duplicates toggle changes the result within 1 to 19

Common mistakes to avoid

• Requesting more than 19 unique numbers. With duplicates off, the pool is fixed at 19 values (1 through 19). Asking for 20 or more unique numbers is impossible since only 19 distinct values exist in this range; widen the range or allow duplicates.
• Assuming 19 is excluded. The maximum is inclusive, so 19 can appear in the result just as easily as 1. The range holds exactly 19 whole numbers, not 18.
• Confusing this with a 20-sided die. A tabletop d20 covers 1 to 20, one more value than this preset. If you specifically need a d20 roll, change Maximum to 20; the 1 to 19 preset is a different, slightly smaller range.
• Expecting a perfectly even spread in a few draws. In a short run of picks from 19 values, you may see repeats or gaps by chance alone. That is normal short-run variance, not a fault in the generator; the fairness of the 1 in 19 odds holds over many draws.

Glossary

Random number generator (RNG)

A process that produces numbers that are hard to predict, with each allowed value equally likely within the chosen range.

Inclusive range

A range where both endpoints count as valid results. For 1 to 19, that means the value 1 and the value 19 can both be generated, alongside everything between them.

Uniform distribution

A spread where every value in the range has exactly the same probability of being chosen, so no number is favored over another.

Cryptographically secure

Randomness drawn from a high-quality system source that cannot be predicted or reproduced, as provided by the Web Crypto API.

With and without replacement

With replacement means each pick is independent and numbers can repeat. Without replacement means each value is used at most once, like dealing cards from a deck of 19.

Modulo bias

A subtle skew that appears when a large random value is reduced with the remainder operator and the range does not divide evenly, making some numbers slightly more likely than others.

Frequently asked questions