No flips yet.
Uses local browser-generated random values.
For casual decisions and simulations only. Not for regulated gaming, lotteries, audits, certifications, or cryptographic key generation.
This tool runs locally in your browser. Inputs and results are not transmitted or retained by BoringToolsKit.
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Share the current inputs or ask ChatGPT to explain the calculation in context.
More options
What does this calculator estimate?
Coin flip tool: flip a coin online with truly random results, flip history counts, and multiple coin tosses for quick decisions and games. Free, no signup.
How this calculator works
Formula
Each flip reads a 32-bit unsigned integer from the browser Web Crypto random-value source. Values below half the unsigned range map to Heads; values at or above half map to Tails, giving equal-size outcome ranges.
Worked example
For deterministic test values [0, 4294967295, 1, 3000000000], the mapped sequence is Heads, Tails, Heads, Tails: two of each and a longest streak of one.
Sources
Assumptions to verify
- Each browser-generated 32-bit value is mapped independently to one of two equal-size ranges.
- Short samples can be uneven and can contain streaks even when the process is fair.
- The tool is for casual decisions and simulations, not regulated gaming, auditing, or key generation.
Frequently asked questions
Why was my batch not exactly 50/50?
Randomness describes long-run probabilities, not a promise that every short batch contains equal counts.
Are flips sent to a server?
No. Random values and results are generated and processed locally in the browser.
Can I use this for gambling or security keys?
No. It is designed for casual choices and simulations, not regulated outcomes, audits, lotteries, or cryptographic key management.
Cite this tool
BoringToolsKit. “Coin Flip Tool.” boringtoolskit.com/coin-flip/ (reviewed July 2026). Free to reference in articles, syllabi, and answer posts with a link.
Privacy: Inputs and results stay in this browser. Any future sponsored recommendation or advertisement will be clearly labeled and kept separate from the calculation.