About the Spread Timer
An infection spreads outward from a handful of random seed cells, filling the screen one cell at a time as time passes. Each round every frontier cell rolls a random chance to infect each of its uninfected neighbors, producing organic, blob-shaped growth instead of a regular fill. By the time the clock hits zero the entire grid is filled.
How It Works
When the timer starts, 3–5 seed cells appear near the center. Each game-step, every active frontier cell rolls a 32% chance per neighbor to spread. Misses stay active so they get retried next round — that's what gives the pattern its rough, finger-like edges. The growth order is fixed at the moment you press start, then the timer fills cells along that order at a pace determined by the duration.
Perfect For
- Visual countdowns — fundamentally different from a bar or clock
- Classrooms and labs — a memorable, conversation-starting timer
- Focus blocks — watch the screen organically fill
- Sensory rooms — slow, hypnotic growth
Features
- Stochastic cellular spread from random seeds
- Different growth pattern every time you reset
- Preset durations and custom time input
- Audio alert on completion
- Fullscreen mode
FAQ
Why does the pattern look different each time?
The seed cells and per-step spread rolls are random, so the growth shape is never the same twice. Hit Reset to see a new pattern.
How many cells fill the screen?
It depends on your screen size — typically several thousand cells. The cell size is fixed; the grid adapts to your canvas.
Is the spread timer free?
Yes — free, no signup. Runs in any modern browser, desktop or mobile.
Can I run it fullscreen?
Yes. Tap the Fullscreen button under the canvas; press Esc to exit.