Random Number Generator 1 to 100
Generate cryptographically random numbers or pick random items from a list. Uses crypto.getRandomValues() — cryptographically secure, not Math.random().
Optional. Commas between values, dashes for ranges.
About random numbers from 1 to 100
A random number from 1 to 100 is the most requested range online, and for good reason: it maps directly onto percentages. Each value has exactly a 1% chance, so a result of 37 can be read as “37th percentile” — the same idea as rolling percentile dice (d100) in tabletop RPGs, where you succeed if the roll is at or below your skill.
Common uses include the classic “guess my number” game (with yes/higher/lower hints, an optimal guesser never needs more than 7 tries), picking a winner from up to 100 giveaway entries, sampling rows from a spreadsheet for spot checks, and deciding events with a given probability — for instance, “if the number is 30 or lower, it happens” gives a 30% chance.
With 100 possible values, repeats still arrive sooner than expected: after 13 independent rolls the chance of at least one duplicate passes 50%. That is the same math behind the famous birthday paradox. If you need each number exactly once — numbering 100 contestants in a random order, for example — use Draw mode or generate 100 unique numbers in Multiple numbers mode and copy the whole shuffled list.
Frequently Asked Questions
What is the chance of getting 100 when picking from 1 to 100?↓
Exactly 1%, the same as any other number in the range. Over 100 rolls, the chance of seeing 100 at least once is about 63%.
Can I use this as a d100 or percentile roll?↓
Yes. A result from 1 to 100 is equivalent to a percentile dice roll; compare it with your target percentage to decide success.
How do I make an event happen with a certain probability?↓
Pick a threshold equal to the percentage you want. For a 25% chance, the event happens when the number is 25 or lower.
How do I shuffle the numbers 1 to 100?↓
Use Multiple numbers with Count 100 and “No duplicates” on, or use Draw mode to reveal them one at a time without repeats.
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