UD5 Toolkit
Today in Random History – Explore Events from the Past
Get a random historical event that occurred on this day or any day of the year. Learn something new and share it as a conversation starter.
Coin Toss History & Statistics - Online Fairness Tracker
Coin Toss History & Statistics
Track, visualize, and analyze your coin flips. Test fairness with real statistics.
Auto
Please enter valid characters: H or T.
Toss History (0)
No flips yet. Start flipping!
Heads
0
0%Tails
0
0%Max Heads Streak
0
Max Tails Streak
0
Fairness Test (Binomial, normal approximation)
Null hypothesis: coin is fair (p = 0.5). Two‑tailed test.
Not enough data. Flip at least once.
Observed heads ratio: -
z‑score: -
p‑value: -
Frequently Asked Questions
It checks whether the observed number of heads deviates significantly from the expected 50% under a fair coin. A small p‑value (<0.05) suggests the coin (or the tossing process) may be biased.
It depends on the bias. Small biases need hundreds or thousands of flips. Our tool uses a normal approximation, which works well for more than ~30 flips. For very small samples the result is just an indication.
Absolutely. Switch to Manual Entry and type H or T exactly as they occurred. The statistics and fairness test will be applied to your real‑life data.
It is the probability of seeing a result as extreme as yours (or more) under a fair coin. If p < 0.05, statisticians often reject fairness. If p > 0.05, the data are consistent with a fair coin.
It uses JavaScript's
Math.random(), which is suitable for statistical demonstrations but not cryptographically secure. For critical applications, use a hardware generator.Yes, click the Export button to download a CSV file with your entire toss history, including index and result (H/T).
Coin Flip Streak Tracker – Visualize Randomness
Flip a virtual coin repeatedly and see the longest streak of heads or tails. Visualize how randomness can produce seemingly non‑random patterns.
Normal Distribution Calculator – PDF, CDF & Z Probabilities
Explore the normal distribution: compute probability density, cumulative probability, and tail probabilities for a given z-score or x value with interactive plot.
Coin Toss Probability Demonstrator – Online Long‑Run Simulator
Virtual flip coins thousands of times and see the heads/tails ratio converge to 50%. Interactive law of large numbers.
RPG Dice Roll Analyzer – Online Probability of 4d6 Drop Lowest
Simulates 4d6 drop lowest many times and shows average stat array. Character creation helper.
On This Day Trivia Generator – Online Historical Events
Shows a random historical event that occurred on today's date. Fun daily knowledge snippet.
Disc Golf Putting Probability Calculator - Online C1X/C2 Stats
Estimate make probability of a putt based on distance and skill rating. For disc golf enthusiasts. Fun statistical tool, no data upload.
Dice Probability Calculator - Online Sum Distribution & Odds
Calculate probability of getting a specific sum when rolling multiple dice. Visual bar chart. Useful for tabletop RPG players. Instant local computation.
A/B Test Significance Calculator - Online Simple Stats Tool
Check if your A/B test results are statistically significant using chi-squared test. Enter visitors & conversions for control/variant. Results in plain English.
Weighted Decision Coin Flip - Online Bias % Customizable
Flip a coin with adjustable bias (e.g., 70% heads). Used for random decision-making when you want to gently influence outcomes. History & stats shown.
Historical Figures Timeline - Online Interactive Life Spans
See famous people's life spans on a draggable timeline. Compare who was alive at the same time. Educational fun.
Pomodoro Timer with History - Online Track Focus Sessions
Pomodoro timer that saves completed sessions to localStorage. View daily/weekly stats. Boost productivity with data.
Advanced Online Scientific Calculator - History & Memory
Full scientific calculator with history tape, memory keys, and unit conversions. All in your browser, no install.
Card Deck Probability Calculator - Online Poker & Draw
Calculate odds of drawing specific cards or poker hands from a standard deck. Learn combinations. Local math.
Dice Roll Simulator & Stats - Online Massive Roll Trials
Roll any number of dice thousands of times and see a live bar chart of the sum distribution. Great for game designers.
Clipboard History Viewer - Online See Last Copies
A small widget that records your clipboard text history (only while open). Search and re‑copy old snippets. No log upload.
Historical Events Today - Online On This Day in History
See a list of notable historical events that happened on this day across years. Static data, no API needed.
Dice Probability Heatmap - Online Visual Stat Calculator
Visualize the probability distribution of dice rolls as a color‑coded heatmap. For any NdM combination. RPG strategist's dream.
Random History Fact Generator - Online On This Day
Get a random history fact or see what major events happened on this day. Curated from public domain sources. Local.
Historical Cameras Timeline - Online Photography Evolution
Scroll through an interactive timeline of cameras from camera obscura to modern DSLR. Photos and facts.
Confidence Interval Calculator - Online Mean & Proportion
Compute confidence intervals for a population mean (known/unknown sigma) and proportion. All popular Z/T values. Local.
Error Function (erf) Calculator - Online Statistics & Physics
Compute the error function and complementary error function for any real x. Quick and precise. Pure frontend math.
Hypergeometric Distribution Calculator - Online Sampler Probability
Calculate probability of k successes when sampling without replacement. Useful for quality control and card games.
Poisson Distribution Calculator - Online Event Occurrence Probability
Compute Poisson probabilities for a given mean rate. Ideal for call centers, traffic analysis. Instant chart.
Bernoulli Trial Calculator - Online Binomial Probability
Calculate the probability of exactly k successes in n independent Bernoulli trials. Step-by-step result. Local.
Bayes' Theorem Calculator - Online Probability Update Tool
Easily compute posterior probabilities given prior, likelihood, and marginal likelihood. Visual diagram. All local.
PRNG Validator - Online Check Randomness Pattern
Paste a list of numbers to visually check uniformity, mean, and simple pattern analysis. Educational tool for statistics and RNG.
Dice Roll Probability Calculator - Online Sum & Graph
Select the number and type of dice, then view the exact probability for each possible sum as a bar chart. Great for board game strategy. Local computation.
Timeline Creator - Online Generate Visual History Chart
Build a vertical timeline by entering events with dates and descriptions. Export as image or HTML. Perfect for project milestones.
Probability Calculator - Online Odds & Combinatorics Tool
Compute probability for simple events, as well as permutations and combinations (nPr, nCr). Useful for statistics and game theory. Browser-based math.