The same five blocks on a level 128 field, so darker and lighter blocks run side by side. These are the grey-to-grey changes a monitor's rated response time describes, timed between the 10 and 90 percent points of the change. The page opens on this pattern.
Pattern
On a screen that holds each frame, your eye smears a shape at this speed across about 16 pixels.
Space pauses. The arrows change speed. F goes full screen.
Slow scroll, 360 pixels a second6 pixels a frame at 60 Hz and 2.5 at 144 Hz, so the smear your own eye tracking adds is narrow. A 10 ms pixel change leaves a 3.6 pixel trail. Start here: at this pace almost everything you see behind the block is the panel.
Reading scroll, 720 pixels a secondThe slowest speed here that is a whole number of pixels a frame at 60, 120, 144 and 240 Hz alike: 12, 6, 5 and 3. Use it to compare two monitors with different refresh rates, and as the speed for the two text patterns.
Steady pan, 960 pixels a secondA 1,920 pixel screen crossed in 2 seconds: 16 pixels a frame at 60 Hz, 8 at 120 Hz, 4 at 240 Hz. A 5 ms change trails 4.8 pixels and a 10 ms change 9.6. The page opens here: halos and fading copies both show clearly.
Show all 30 speeds, patterns and trails (27 more)
Speeds, continued
Fast pan, 1,440 pixels a second24 pixels a frame at 60 Hz, 10 at 144 Hz, 6 at 240 Hz. On a 60 Hz screen eye tracking alone now smears every edge by 24 pixels, which can bury a short trail. Better at 120 Hz and above, where the smear is 12 pixels or less.
Quick turn, 1,920 pixels a secondA full HD screen width every second, the speed of a quick camera turn in a game. A 10 ms pixel change now trails 19.2 pixels and a 5 ms change 9.6. At 60 Hz the block jumps 32 pixels a frame, so judge this speed on a faster screen.
Flick, 2,880 pixels a secondThe top speed: 12 pixels a frame at 240 Hz and 48 at 60 Hz. Each millisecond of pixel response is 2.88 pixels of trail, so even a quick panel shows something. Use it to tell two fast overdrive levels apart, never as a first test.
Moving patterns 10
Grey ladder on blackFive blocks, levels 0, 64, 128, 192 and 255, cross a black field together. Each pixel rises from black as a block's front edge arrives and falls back as it leaves. A dim, soft front edge is a slow rise. A tail behind the block is a slow fall.
Grey ladder on mid greyThe same five blocks on a level 128 field, so darker and lighter blocks run side by side. These are the grey-to-grey changes a monitor's rated response time describes, timed between the 10 and 90 percent points of the change. The page opens on this pattern.
Grey ladder on whiteDark blocks on a white field are what black text on a white page is made of. A grey tail behind the black block is pixels climbing back to white too slowly. Run all three ladders before you settle on an overdrive level: one clean ladder proves little.
Near-black block on blackOne block at level 32 on a field at level 0, the smallest and darkest step on the page. A panel has a different speed for every pair of shades, and one rated figure cannot describe them all. Dim the room and look for a long, smoky tail.
Near-white block on whiteLevel 223 on level 255, the matching small step at the bright end. A pale button makes this change when you scroll a white page. Compare it with the near-black block: clean on one and smeared on the other means the panel is slow at that end of its range.
Thin white lines on black, 1, 2 and 4 pixels wideA moving line one pixel wide lights each pixel it lands on for a single frame. If the rise takes longer than that frame, the pixel never reaches full white. Press the space bar to pause: a line that is dimmer moving than still means slow rises.
Thin black lines on white, 1, 2 and 4 pixels wideThe reverse case: each pixel must fall to black and recover inside one frame. A one pixel line that turns grey or vanishes while moving, yet is solid black when paused, shows the falls are slow. Small moving text fades for the same reason.
Scrolling text, black on whiteLines of our own text at 12, 16 and 24 pixels slide across the lane. Find the smallest size you can still read at 720 pixels a second, then compare that size after each change to the monitor's menu.
Scrolling text, white on blackDark mode. Every letter stroke is a rise from black followed by a fall, and the streak trailing each letter as it slides is the fall running late. If this looks worse than black on white, your panel falls to black more slowly than it climbs to white.
Colour blocks on mid grey: red, green, blue and yellowEach pixel is three sub-pixels, and each makes its own change. A red block leaving a grey field asks red to fall and green and blue to rise. If one of them overshoots, the fringe takes a colour found in neither the block nor the field.
What you see, and what causes it 8
A soft smear as wide as one frame of travelNot ghosting. The screen holds each frame still while your eyes keep gliding, so the image smears across your retina. Its width is speed divided by refresh rate: 16 pixels at 960 pixels a second on 60 Hz, 6.7 on 144 Hz. The bar under the pattern chips gives yours.
A fading copy trailing behind the blockConventional ghosting: pixels behind the block are still changing back to the field's shade. The tail is always a shade somewhere between the block and the field, and it is longer than the bar under the pattern chips. Raise overdrive one step and run the same pattern again.
A bright halo behind the blockOvershoot, also called inverse ghosting. Overdrive has pushed the pixels past the shade they were aiming for, so the tail is brighter than both the block and the field. No slow pixel can do that. Lower overdrive one step.
A dark shadow behind a light blockThe dark form of overshoot. The pixels have been driven below the field's shade on their way back, leaving a dirty edge darker than both block and field. Compare it with the field a few centimetres away to be sure. Lower overdrive one step.
A coloured fringe that matches neither block nor fieldOvershoot halos can be colourful, because red, green and blue sub-pixels overshoot by different amounts. The tell is a tint on a plain grey block, which has no colour of its own to smear. Treat it as overshoot: go down one overdrive step, then check the colour blocks pattern.
Two or more sharp copies of the blockThe picture is reaching your moving eye in separate flashes. A backlight dimmed by pulsing can flash several times a frame, and a page drawing at half the screen's rate shows each position twice. Set brightness to full, where a backlight has no need to pulse, and look again.
Jumps and stutter, with sharp edgesFrames are being dropped before they reach the screen, so the block skips ahead. That is the browser or the computer, never the panel. Close other tabs and plug a laptop in. The page says so when frames are being dropped.
A trail on one ladder and not on the othersNormal, and the reason there are three ladders. Every pair of shades has its own response time. On many VA panels the quickest shade changes are several times faster than the slowest, even with overdrive on. Tune for the ladder closest to what you watch.
What to change, and how to check it 6
Overdrive, one step at a timeOverdrive sends each pixel a stronger voltage than the new shade needs, then eases off, so the change finishes sooner. Monitor menus call it Overdrive, Response Time or a maker's own name. Start at the lowest level and keep the highest one that shows no halo.
Refresh rate at the panel's maximumA new monitor can sit at 60 Hz until you change it in the operating system's display settings, and some cables and ports cap it. Going from 60 to 120 Hz halves the frame time, from 16.7 to 8.3 ms, and halves the eye-tracking smear with it.
Backlight strobing or black frame insertionBoth cut blur by showing each frame for less time: an LCD flashes its backlight, an OLED switches its pixels off between frames. The picture gets dimmer, and if pixels are still changing when the flash comes you see a second faint copy. Test with it on and off.
Motion smoothing on a TVMotion interpolation invents frames between the real ones. It reduces blur on film and sport, adds input lag, and makes this test meaningless, because the TV is redrawing the blocks itself. Switch to game mode, or turn smoothing off, before you judge the panel.
Variable refresh rate with a falling frame rateOverdrive is normally tuned for the top refresh rate. When a game runs slower and the screen follows it down, the same level overshoots for longer, so halos appear that this page never showed. Some monitors retune overdrive as the rate moves. Many do not.
A photo of the trailA still camera with a fast shutter records what the pixels are doing, without the smear your tracking eye adds, so it is fair evidence of a halo. To capture what you see, reviewers slide the camera along with the target, called pursuit photography.
How this list was compiled: Speeds, patterns, signs and settings written for this page; the moving shapes are this site's own plain blocks, lines and text. Every figure was computed: pixels a frame and eye-tracking smear are speed divided by refresh rate, trail length is speed times response time, frame time is 1,000 ms divided by the refresh rate. The cause of eye-tracking blur on a screen that holds each frame, the worked example of a 1,920 pixel screen crossed in 2 seconds at 60 Hz, backlight strobing, black frame insertion, OLED response times being far shorter than LCD, and motion interpolation adding input lag are from https://en.wikipedia.org/wiki/Display_motion_blur. Response time measured grey to grey between the 10 and 90 percent points is from https://en.wikipedia.org/wiki/Response_time_(technology). How overdrive works (a higher first voltage that then eases off) is from https://en.wikipedia.org/wiki/Response_time_compensation. Overshoot and inverse ghosting, its bright, dark and colourful forms, VA grey-to-grey changes that stay above 10 ms while others reach about 4 ms, and overshoot lasting longer when a variable refresh rate falls are from https://pcmonitors.info/articles/factors-affecting-pc-monitor-responsiveness, which the Wikipedia response time article cites. Backlights dimmed by pulsing at rates from 180 Hz to several kHz are from https://en.wikipedia.org/wiki/Flicker_(screen). The limit of three flashes in any one second that the moving shapes are designed to stay under is from https://www.w3.org/WAI/WCAG22/Understanding/three-flashes-or-below-threshold.html. All checked 2026-09-19. Licence: own work
How it works
This ghosting test slides black, grey and white blocks across your screen. Match the trail you see under What to look for and the monitor ghosting test names its cause: slow pixels, too much overdrive, or your own eye tracking.
Read the full guide
How to check monitor response time by eye
A slow pixel leaves a tail shaded between the block and the field: that is ghosting, and its length is speed times response time. At 960 pixels a second, a 10 ms change leaves a 9.6 pixel trail. A tail brighter or darker than both is overshoot. Smear no wider than the bar under the pattern chips is your eye tracking, not the panel.
Tune overdrive step by step
Overdrive pushes each pixel harder than the new shade needs: too little leaves a fading copy, too much throws a halo. Start at the lowest level, run all three grey ladders and note Trail, Clean or Halo for each, then go up a step. Keep the highest level with no halo.
Wait until the line under the pattern name reads Measured. 60 Hz on a faster monitor? Fix display settings first.
Questions and answers
Is this a monitor response time test?
By eye, yes: it shows what slow pixels do, with no figure in milliseconds, since a web page cannot time a pixel. Makers rate response time between the 10 and 90 percent points of a grey-to-grey change, which leaves the slow last part out.
Is this also a motion blur test?
Yes: it shows both kinds of blur. Ghosting belongs to the panel, whose pixels take too long to change. Eye-tracking blur appears on any screen that holds each frame still, however fast its pixels. Keyboard ghosting is unrelated: see the rollover test.
Can I run a screen ghosting test on a laptop, phone or TV?
Yes, anywhere a browser runs. The page measures the rate the browser draws at, which battery saver can hold below the panel's own. OLED pixels change faster than LCD pixels, so an OLED mostly shows eye-tracking smear. On a TV, switch to game mode first.
Why do trails look worse in games?
Overdrive is tuned for the top refresh rate. With variable refresh rate on and a game running slower, the same level overshoots for longer, so halos appear. If your monitor does not retune overdrive as the rate moves, choose a lower level for slower games.