How to play "draw a perfect circle"
- Put your finger, stylus or mouse near the dot and draw a circle around it in one continuous stroke.
- Your score updates while you draw. When you let go, the line is coloured from green (spot on) to red (off course), and a dashed guide shows the ideal circle.
- Your best score is kept on this device. Share your result and challenge friends to beat it.
How the score is calculated
Every point of your drawing is measured from the centre dot. The average of those distances is your circle's radius, and the score reflects how far your line strays from that radius on average: a perfect circle has every point at exactly the same distance. A gap between the start and the end of your stroke costs a few points, and you must go almost all the way around the dot for the attempt to count. Drawing straight through the dot, or a very small circle, is rejected.
Scores in the 80s are good, the 90s are excellent, and 95% or more is rare. The game was popularised by Neal Agarwal's neal.fun, and it is surprisingly addictive; it is also a nice way to warm up your hand before sketching or handwriting practice.
Tips for a better circle
- Move your whole arm from the shoulder or elbow, not just your wrist or finger.
- Draw at a steady, fairly quick speed. Slow lines wobble.
- Larger circles are easier to keep round than tiny ones.
- Look at the dot, not at your pen.
Your drawing stays in your browser; nothing is uploaded.
Is it possible to get 100%?
Practically no. Even a steady hand varies by a few pixels, so the best human scores are in the high 90s.
Does it work on phones?
Yes. The canvas scales to your screen and supports touch and stylus input.
Why was my circle rejected?
It was too small, too short, did not go all the way around the dot, or passed through the centre.