What is time perception?
Time perception is your sense of how much time has passed. Psychologists test it in several ways; this test is a time production task: you produce an interval yourself, by stopping a hidden timer when you think the target time has gone by. Your result shows how closely your inner sense of time matched the clock.
How this test works
There are 3 rounds, with targets of 5, 10 and 15 seconds. In each round you press Start timer, wait, and press Stop when you think exactly the target time has passed. No clock is shown and nothing on the screen moves while the timer runs, because anything that moves could be counted.
After each round you see the time you actually stopped at and how far off you were, early or late. You can use the button, the Space bar or Enter.
How we calculate your result
The interval is measured between the two presses, using the timestamp your browser gives each press when it arrives, taken on the press down. Whatever small delay your mouse, keyboard or touchscreen adds, it adds to both presses, so it almost entirely cancels out. That makes this the least device-dependent challenge on the site.
For each round we take the difference between your interval and the target: stopping at 10.42 seconds for a 10-second target is 0.42 seconds late. Your result is the average of the differences across the rounds, ignoring whether each was early or late, so being 0.5 seconds early and then 0.5 seconds late averages to 0.5, not zero. The list under your result keeps the direction of each round.
Longer targets, bigger misses
Expect to be further off at 15 seconds than at 5. Being 5% off is a quarter of a second at 5 seconds but three quarters of a second at 15. If you want to compare rounds with each other, divide each difference by its target.
Counting or not counting
You're allowed to count in your head, and it's worth trying the test both ways: one run counting steadily, one run going purely on feel. Comparing the two shows how different keeping a steady rhythm is from judging a stretch of time by feel.
What this test does not measure
It measures how closely you can produce three set intervals in one sitting. Your attention, your mood and whether you count all change the result. It isn't a medical or psychological assessment.
If you want a challenge where speed is the whole point, try the Reaction Time Test or the sound-based Audio Reaction Time Test.