How to choose a tool
- Need fairness with different chances? Use the weighted picker.
- Need simple winners from a list? Use the random picker.
- Need to prove fairness later? Use the verifiable draw (commit-reveal).
- Need probability insight? Use the probability calculators.
Recommended (top 3)
If you are unsure where to start, these cover most “random” use cases.
Tools
- Weighted Random Picker – random choice with weights | CalcBE
Pick random items with weights (probability ratios). Use an optional seed for reproducible draws and share your setup via URL—runs locally in your browser.
- Verifiable random draw (commit-reveal) – auditable picker | CalcBE
Run a verifiable random draw using a commit-reveal scheme. Publish a commitment hash first, reveal the seed later, and let anyone reproduce and verify the results—runs locally in your browser.
- Random Picker | Draw winners without repeats
Pick one or more random items from a list in your browser. Great for lotteries, giveaways, and classroom activities. Everything runs locally without sending data to the server.
- Random Number Generator | Integers, decimals, seeds
Generate random integers or decimals in your browser with optional seeds, unique values, and copyable results. Everything runs locally without sending data to the server.
- Dice Roller for d4-d100 rolls with PNG sharing | CalcBE
Roll d4-d100 with quick buttons or notation like 2d6+3, see totals and breakdowns, keep history, and share text or PNG cards directly from your browser.
- TRPG dice check – d20 advantage/disadvantage and dice pool successes | CalcBE
Run quick d20 checks with advantage or disadvantage, compare against a DC, and roll dice pools to count successes directly in your browser. Keep rolls local, save history, and share logs as text, PNG cards, or prefill…
- Dice stats – success odds & distribution calculator | CalcBE
Compute success probabilities, exact or simulated distributions, mean/SD, and top modes for NdS +/- K dice notation. Auto switches Exact/Sim, shows histograms, and shares as text, PNG, or URL entirely in the browser.
- Dice tools | Roller, TRPG checks, dice stats | CalcBE
Browser-only dice tools: a dice roller, TRPG dice checks, and Dice stats for success odds and distributions.
Calculators
- Probability Simulator — coin, dice, roulette (theory vs empirical, with steps) | CalcBE
Simulate coin tosses, dice rolls and roulette spins with a fixed seed to compare theoretical and empirical probabilities. Inspect confidence intervals, convergence charts and shareable runs.
- Probability tree & 2×2 table — AND/OR & complement | CalcBE
Probability tree & 2×2 table tool for AND/OR/NOT and complements. Highlights matching paths/cells and explains products, sums, and 1−P with steps. Copy a shareable URL, SVG, or LaTeX.
- Histogram & cumulative frequency from grouped data | CalcBE
Enter grouped or raw data to build a derived frequency table, histogram (frequency or frequency density), and cumulative frequency ogive. Detect unequal widths, highlight modal/median classes, copy a shareable URL, an…