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More distance and less surface area require greater precision.
UX principle 01
How fast can you hit it?
Two rounds. Eight targets. Your own hands will explain Fitts's Law better than a paragraph ever could.
Ready to playFeel the difference
Best hit0 ms
Targets0 / 8
Experiment progress
Your results
The difference is physical.
Complete both rounds to compare your average movement time and reveal what changed.
Ready
A generous target reduces effort and speeds up the action.
Play first
Your personalized result will appear here.
Now the theory
This feeling has a name.
Time ≈ distance ÷ target size
Fitts's Law predicts that a target takes longer to reach when it is smaller or farther away.
In interface design, every button, link and tap area is a target. Making an important action easier to reach is not decoration. It directly reduces effort for the person using it.
Fictional shopping cart
One last challenge
Fix the checkout.
What is the most important improvement according to Fitts's Law?