Probability
Flip a coin, roll a dice. Runs entirely in your browser, so your data never leaves your device.
Output
The result appears here as you type.
How to use Probability
- 1. Choose the experiment. Pick Flip a coin or Roll a dice from the Experiment setting, depending on which random process you want to simulate.
- 2. Set the number of trials and sides. Choose Times for how many flips or rolls to simulate, and Sides for the number of faces on the dice if you selected that experiment, for example 6 for a standard die.
- 3. Pick a separator. Choose commas, spaces, or newlines to join the results, matching whether you plan to paste them into a spreadsheet column or a line of text.
- 4. Generate and copy the results. The simulated outcomes appear in the output pane, each flip as H or T and each roll as a number. Copy them for statistics practice or a probability simulation.
When to use Probability
Probability simulates repeated coin flips or dice rolls and returns the outcomes as a list. Use it whenever you need randomized trial data quickly, without physically flipping coins or writing a random number generator yourself.
- Generating data for a statistics assignment. A homework problem asks you to flip a coin 50 times and compute the observed frequency of heads, and generating the trial outcomes here gives you real data to analyze instead of making numbers up.
- Testing a probability simulation script. You are writing code that models dice rolls for a board game or gambling simulation and want a quick reference set of rolled outcomes to sanity-check your random number handling.
- Running a tabletop game session shortcut. You need to roll a d20 several times quickly for a tabletop RPG encounter and want the results as a list rather than rolling physical dice one at a time.
- Demonstrating the law of large numbers. A classroom demonstration shows how the fraction of heads approaches 0.5 as the number of coin flips grows, and generating thousands of flips at once makes the convergence visible quickly.
Examples
Ten coin flips
Output
H T T H H T H H T H
About the Probability tool
Probability is a free online tool that works entirely inside your web browser. Flip a coin, roll a dice. Because the processing happens on your own device, nothing you enter is uploaded, logged or stored anywhere.
This page is one of 234 Math utilities on EditSafely. Each one does a single job well, and all of them follow the same rule: your input stays on your machine.
You can shape the output with 4 settings, including Experiment, Times, Sides and Separator, and the result refreshes the moment you change one. A worked example further down the page shows exactly what the tool produces for a real input.
Because nothing leaves your device, the tool is suitable for sensitive content such as internal documents, credentials or customer data. It also responds instantly, since every keystroke is handled on your own machine rather than by a remote API.
Frequently asked questions
Does Probability cost anything?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Does the generator send anything to a server?
No data leaves your device. The whole tool is JavaScript that runs inside your browser tab, so there is no upload, no server-side processing and no log of what you did. If you disconnect from the internet after the page loads, it keeps working.
How do I get a different result?
Run the generator again. Each run is computed fresh on your device, and any options you change are applied to the next result immediately.
Do I need to sign up or install anything?
Nothing to install and no account needed. Open the page in any up-to-date browser, including on a phone or tablet, and the tool is ready.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.