3D Dice Roller & Coin Flip
Free, private and calculated in your browser
Roll dice
Type a dice formula. Every roll uses cryptographically secure randomness.
Your dice appear here. Try the examples below.
Formula examples
1d20One 20-sided die — attack or save roll2d6+3Two 6-sided dice, add 3 to the total4d6Four 6-sided dice — ability score roll1d100Percentile roll from 1 to 1002d10+1d4Mixed dice in a single formula3d8-2Three 8-sided dice, subtract 2
Supported dice: d4, d6, d8, d10, d12, d20 and d100. Up to 100 dice per expression.
Flip a coin
A fair 50/50 flip — useful for quick decisions, sports and games.
Tap flip to start
About this tool
3D Dice Roller & Coin Flip is a privacy-first utility designed to finish a small everyday task without an account, remote API or server-side data store. Inputs are processed in the browser and the visible result is available immediately, including when the calculation itself is performed offline.
The interface keeps the important caveats beside the result. Sensor readings are labeled as estimates, dates and financial projections expose their assumptions, and health or travel information includes a clear reminder to confirm decisions with an appropriate professional or official authority.
How to use
Choose a mode
Open the tool and select the measurement, calculation or study mode that matches your task.
Enter local values
Use the labeled inputs and sample values. Permission-based features request access only after you press their start button.
Review the result
Read the result and its limits. Time-sensitive tools use absolute timestamps so background tabs do not create drift.
Export or reset
Copy or download only when needed, and reset the form when you finish on a shared device.
Use cases
Quick personal workflow
Use it for a one-off measurement, conversion, study session or planning estimate without creating a profile.
Offline and private work
Keep notes, values and local records in the current browser session when connectivity or data sharing is undesirable.
Common mistakes
Mistake:Treating an estimate as a certified measurement or official decision.
Fix:Read the tool disclaimer and use calibrated instruments or official sources when accuracy has legal, medical or safety consequences.
Mistake:Leaving sensitive values open on a shared device.
Fix:Export only the information you need, then clear the form or close the private browser session.
Frequently asked questions
Related guides
Picking a Random Number (or a Raffle Winner) Without a Server
How a browser-only raffle picker avoids the classic mistakes — modulo bias, duplicate winners, predictable seeds — using the Web Crypto API.
Fair Random Picks With crypto.getRandomValues
Why Math.random() isn't the right primitive for a decision wheel, and what cryptographically strong randomness actually buys you for a fair pick.
References & standards
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