Weighted Random Picker
Paste a list of "label : weight" pairs and the picker draws using the cumulative-sum method against crypto.getRandomValues — so heavier options come up proportionally more often. Useful for A/B test allocation, weighted team-pairing, fair-but-biased gift exchanges, or anything where a flat coin flip would feel unfair. Toggle replacement off to draw N distinct options when you need a ranked subset.
- Alice20.0%
- Bob6.7%
- Carol33.3%
- David13.3%
- Eve26.7%
Replacement on = each draw is independent (options can repeat). Off = picked options are removed.
Press Pick to draw.
Weights can be any positive numbers (not just integers). The picker uses crypto.getRandomValues for cryptographically random draws.
How to use
- List your options one per line as "label : weight" or "label, weight" (any positive number).
- Pick how many draws and whether the same option can come up twice.
- Read the probability table to sanity-check that your weights match your intent before pressing Pick.
Frequently asked questions
- What's the difference vs the regular Random Picker?
- Random Picker treats every entry as equally likely. Weighted Picker lets you put a thumb on the scale — e.g., give one teammate a 30% chance and four others 17.5% each instead of a flat 20%.
- With replacement vs without?
- With replacement = each draw is independent and the same option can repeat. Without = each draw removes the picked option from the pool, so N draws give N distinct items (and N can't exceed the option count).
- Do the weights have to add up to 100?
- No. Only the ratios matter: the picker divides each weight by the total, so 1 : 3 behaves exactly like 25 : 75 and like 10 : 30. That is why the displayed probability is worth reading after an edit — it is the number the draw actually uses, and it makes a typo in one row visible as a shifted percentage everywhere else.
- I ran twenty draws and the heavy option did not win twenty times its share. Is the weighting working?
- Probably, yes. Weights describe the chance of each individual draw, not a quota to be filled over a run: at twenty draws the spread around the expected counts is wide, and a two-to-one favourite losing a short series is unremarkable. If you need exact proportions rather than probabilities, draw without replacement from a list that already repeats each option as many times as its weight.
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