Game
Jump the cacti, duck the birds, and the speed climbs the further you get. Written from scratch on a canvas, with fixed-step physics so it plays identically on any refresh rate.
Click the canvas or press space to start
How to
How to play
The measurement
How it is built
A jump arc driven by frames runs twice as fast on a 144Hz screen as on a 60Hz one, which is a bug players feel as unfair difficulty. Here time is accumulated and consumed in fixed slices, so the arc is identical everywhere.
The catch-up is capped as well. A tab that was hidden for a minute does not resume by simulating a minute of movement at once — it would run the player straight into an obstacle they never saw.
The bench
Every tool on the bench
One instrument per input, all on the same clock. A rate is only comparable against the same tool and the same interval.
Background
Read the method
Longer entries on what this tool measures and where the number comes from.
Questions
Asked of the chronometer
You can jump — a tap anywhere on the canvas does it. Ducking is bound to the down arrow, so the low-flying birds that appear a few hundred metres in need a keyboard. On a phone, treat those as the end of the run.
Jump later than feels right. The arc is fixed, so an early jump lands you in front of the obstacle rather than past it, and the higher the speed climbs the more an early jump costs. There is no double jump to rescue a mistimed one.
Yes, in this browser. It survives a refresh and a closed tab, and it is not uploaded anywhere — a different device or a private window starts from nothing.