Random Number Generator 1-20
Generate a random integer from 1 to 20, with both ends included.
This page returns integers from 1 to 20 — each number has a 5% chance. The range is fixed so you can generate again without re-entering the bounds.
Typical use: rolling a d20, picking from a list of twenty, or a 1-in-20 chance. If you need a different range, the fields above are editable; the URL stays on this page and nothing is submitted anywhere.
How to use it
- Press generate — the range is already set to 1-20.
- Turn on no-repeats if you are drawing several winners from the same set.
- Copy the result, or keep generating; each result is independent.
Why the range stops at 20
Twenty is the standard polyhedral die for tabletop games, and 5% is an easy probability to reason about. With 20 possible values, the chance of any specific number coming up is each number has a 5% chance.
Generating with a narrow range is not the same as generating a wide range and rejecting out-of-range values. Filtering like that biases the result towards whatever is left; this tool draws directly from the range you set, using rejection sampling on the raw random bits.
Reviewed 2026-10-21. This tool runs entirely in your browser — no server, no account, and nothing you generate is stored.
Frequently asked questions
Is this the same as a d20 roll?
Yes, uniformly distributed from 1 to 20. If you need modifiers, advantage or multiple dice, use the dice roller — this page is the single-roll case.
Is 1 or 20 more likely than the middle values?
No. Each of the 20 values has an identical probability. If you generate a few hundred results, the counts should converge towards equal — small samples always look lumpy.
Can I generate more than one number at once?
Yes. Set the count above; leave no-repeats off if duplicates are acceptable, turn it on if you are drawing distinct winners.
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