How the Coin Flip & Dice Roller Works
Click to flip the coin or roll up to 6 dice. Results use crypto.getRandomValues() — the same cryptographic RNG browsers use for HTTPS, so outcomes are statistically indistinguishable from true randomness. In other words, it's not just Math.random().
The coin section logs your last 10 flips with a running heads/tails count. The dice section shows the last 5 rolls with individual die faces and totals.
Tips for Fair Decision Making
- Assign outcomes before flipping. Decide which side means which outcome before you flip, not after — post-hoc assignment defeats the purpose entirely.
- Notice your reaction. The moment the result appears, pay attention to how you feel. Disappointment reveals your true preference more honestly than extended deliberation.
- Two dice = 7 is most likely. With two d6, 7 can be made 6 ways out of 36 combinations. 2 and 12 each have only one way — six times rarer. Useful to know for board games.
When to Use a Coin Flip vs Other Random Tools
A coin flip is ideal for binary decisions where you want a fair, fast, no-fuss outcome — go vs. stay, A vs. B, you vs. me. The moment a third option appears, a coin stops being the right tool. Here's the decision tree:
- 2 outcomes, equal weight. Coin flip — that's what it's built for.
- 3 to N outcomes, equal weight. Use the Decision Wheel for visual spinning, or the List Randomizer if you want to keep all options ranked instead of picking one.
- Number in a range. Lottery numbers, dice with custom sides, picking a random page — the Random Number Generator handles arbitrary min/max with no-duplicate options.
- Weighted choices. If outcomes shouldn't be 50/50, use the weighted-coin slider in the widget above (set to 70/30 or whatever bias you need). For more than two weighted choices, the List Randomizer supports per-item weights.
More flips, a tally, and a weighted-coin slider
History now keeps your last 20 flips — up from 10 — with a live tally: Heads X (Y%) / Tails Z (W%). The percentages track back toward 50/50 as you add more flips, which is satisfying to watch after a lucky streak. The multi-flip SegmentControl lets you throw 1, 5, 10, or 100 coins at once. Flip 100 to run a quick informal probability check; the tally will land close to 50/50 within a few batches.
The weighted-coin slider defaults to 50 % and lets you bias it — say 70/30 — for tabletop game scenarios or to simulate an unfair coin. No rigging mode that auto-picks a winner, no sound effects. Both the coin and dice still use crypto.getRandomValues(), including when the coin is weighted.
Frequently Asked Questions
Is the result actually random or just pseudo-random?
crypto.getRandomValues(), the same RNG browsers use for HTTPS. It's statistically indistinguishable from true randomness and can't be predicted or reproduced.If I got 5 heads in a row, is tails more likely next?
Can I flip multiple coins at once?
Are real coins actually 50/50?
When should I use a coin flip vs a Decision Wheel?
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By Bam's Thinkery — Updated