How Many FPS Can Your Eyes See?

weirdly accurate.

How Many FPS Can Your Eyes See?

How many FPS can the human eye see?

There is no single number, because the eye does not see in frames. What can be measured is how brief a picture can be and still be read before the next one wipes it: in a 2014 study by Mary Potter and colleagues at MIT, people could still tell what a photo showed when each one was on screen for 13 milliseconds, shorter than a single frame on a 60 Hz screen.

This eye FPS test measures that glimpse. An arrow flashes for a whole number of your screen’s frames, a mask of arrow scraps wipes it, and you say which of four ways it pointed. Each level is a frame rate — n frames on an H Hz screen is one picture of a film at H/n fps — so a 60 Hz screen has eight levels from 5 to 60 fps and a 120 Hz screen eleven. One right answer climbs a level; the first miss gets a second try, the second ends the run. Your top level, in fps and milliseconds, is shown against where the middle two-thirds of 641 Dutch adults from an inspection-time study (Posthuma, de Geus & Boomsma, 2001) would land on the same ladder: about 15–20 fps at 60 Hz, 15–24 fps at 120 Hz.

It is not an eye exam and it does not measure intelligence. The comparison is rough: that study flashed two lines rather than an arrow, on 2001 lab screens, and nobody has measured how much easier arrows on a phone are, so there is no percentile. A guess among four arrows is right one time in four, so one run lands within about a level of where you would settle, and glare, a small screen or a long day can each cost a level. A flash your screen stutters on is shown again instead of counted.

What the test measures

One thing: the shortest flash you can still read when the next picture wipes it straight away.

The task

  • A masked flash, as in inspection-time studies: an arrow appears, a mask of arrow scraps covers it, and you say up, down, left or right
  • Every level is a frame rate your screen can really show, built from whole frames at its measured refresh rate: eight levels at 60 Hz, eleven at 120 Hz
  • One right answer passes a level; the first miss gives a second try at the same level with a new arrow, and the second miss ends the run
  • Flash lengths are timed from the screen’s own frame timestamps; if the screen stutters, you still see whether you were right, but that flash doesn’t count

Your result

  • Your top level as a frame rate in fps, and as a flash length in milliseconds
  • Where most people land on your screen’s ladder: the middle two-thirds of 641 adults from a 2001 inspection-time study, carried across to this task
  • A screening report with every flash you saw, plus the three different things people mean by the eye’s ‘frame rate’: the glimpse, flicker and motion
  • A shareable card and a link that challenges a friend to climb higher

Before you start

  • About ten flashes, one minute
  • Works on phones and computers; a 120 Hz screen gets more levels, up to 120 fps
  • A dim room and no glare on the screen help; keep your eyes on the dot in the middle
  • Sound effects are optional; answer with the buttons, a swipe or the arrow keys

Eye FPS FAQ

Is this test free? Do I need to sign up to see my result?

Yes, it’s free, and there’s nothing to sign up for: no account, no email, no payment. Your result appears on this page the moment you finish, and you can share it or play again straight away.

Can the human eye see more than 60 fps?

Yes, in the sense that the eye has no frame rate to run out of. In Potter and colleagues’ 2014 study, people could still detect what a photo showed when each picture was on screen for 13 milliseconds, shorter than one frame at 60 Hz. How smooth motion looks and when a flickering light starts to look steady are separate questions with their own limits, so no single fps figure answers all three.

What is a normal result on the eye FPS test?

On a 60 Hz screen, most people would land between about 15 and 20 fps, and between 15 and 24 fps on a 120 Hz screen. That band is the middle two-thirds of 641 Dutch adults in Posthuma, de Geus and Boomsma’s 2001 inspection-time study, carried across to this ladder. Their task flashed two lines, not an arrow, so treat it as a rough guide; that is also why the test gives no percentile.

Why did I get a different FPS result on another phone?

The ladder is built from your screen’s frames: a 60 Hz screen offers eight levels up to 60 fps, a 120 Hz screen eleven up to 120 fps. Screen size, brightness and glare also change how readable a flash is. Even on the same screen a run lands within about a level either way, partly because a guess among four arrows is right one time in four.

What does “faster than your screen” mean on the eye FPS test?

“Faster than your screen” means you cleared the top level, a single frame — about 17 milliseconds on a 60 Hz screen — so the screen ran out of faster flashes before your eyes did. Because a guess can pass a level one time in four, play again to see whether it holds. A faster screen would let you climb further.

Does the eye FPS test measure eyesight or IQ?

No. The eye FPS test is not an eye exam or an intelligence test. Inspection time, the lab measure it borrows from, has been studied alongside IQ — the 641-adult study behind the ‘most people’ band was about that link — but one short run of arrows on a phone says nothing about your intelligence or eye health. If your vision has changed, see an optometrist or eye doctor.

Where the numbers come from

The ‘most people’ band carries the middle two-thirds of the 641 adults in Posthuma et al. (2001) onto this ladder: their score, correct glimpses per second from a curve fitted as in Luciano et al. (2001), is converted to the flash read 7 times in 10 and then, by simulation, to where a two-miss climb usually ends. Their task flashed lines, not arrows, so there is no percentile. The site does not publish its own players’ data.