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 | CalcBE
Generate random integers or decimals in your browser with optional seeds, unique values, and copyable results. Runs locally — no sign-in, no uploads.
- Dice roller (d4–d100) with PNG sharing | CalcBE
Roll d4–d100 with quick buttons or 2d6+3 notation. Totals, breakdowns, local history, and share as text or PNG — no sign-in.
- TRPG dice check (d20/d100, pools) with PNG sharing | CalcBE
Run d20/d100 checks with advantage/disadvantage, compare vs DC, and roll dice pools to count successes. Share as text, PNG, or URL — all in your browser.
- Dice stats (odds & distribution) + PNG sharing | CalcBE
Compute odds and distributions for NdS +/- K. Auto switches Exact/Sim, shows a histogram, and lets you share as text, PNG, or URL — in your browser.
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…