Tooldeon

Monitor ghosting test

Press Start and four rows of blocks slide across the screen. Watch the blocks and the edges behind them. A faint copy trailing the block is ghosting, a bright or dark halo is overshoot. Try the speeds one after another.

Press Start to begin. Frames are drawn only while the test runs.

This is a visual test, not a measurement. Your eyes judge the trails, and the result depends on the monitor's overdrive setting, refresh rate and your browser's frame rate.

Runs in your browser: nothing you enter is sent anywhere.

How to use it

  1. Set your display to its normal refresh rate and keep the tab visible.
  2. Pick a speed and press Start.
  3. Follow one block with your eyes and look at the area it just left.
  4. Repeat at another speed, and compare rows: black on white and white on black are the strictest.

What each row shows

  • White on black and black on white are the largest brightness jumps, so slow pixels show the longest trails.
  • Gray on dark gray is a small change. Many monitors are slowest here, and overshoot is most visible.
  • Red on blue checks color transitions.

Worked example

At 960 px/s with the browser drawing 120 frames per second, a block moves 960 / 120 = 8 px per frame. A trail several blocks of 8 px long behind it means the pixels need several frames to settle.

Tips

  • Turn the monitor’s overdrive setting up or down one step at a time and run the test again.
  • Compare at the highest refresh rate your monitor supports.
  • A fast block on a 60 Hz screen will look blurrier than on 144 Hz even with perfect pixels.

Frequently asked questions

What is monitor ghosting?

Ghosting is a faint trail behind a moving object. It appears when pixels change color too slowly to keep up with the picture, so the previous frame is still partly visible.

What is the difference between ghosting and overshoot?

Ghosting is a dull trail from pixels that are too slow. Overshoot, also called inverse ghosting, is a bright or dark halo that appears when the monitor's overdrive pushes pixels too far past their target color.

Which speed should I use?

Start with 960 px/s and go up. Faster motion makes trails longer and easier to see. The step per frame shown on the page is the speed divided by the frames per second the browser reaches.

Why do I see no trails on an OLED screen?

OLED pixels change color very fast, so there is little pixel-response ghosting. You may still see motion blur from the way the eye tracks a moving object on a sample-and-hold display.

Does the test stop when I switch tabs?

Yes. Animation stops when the tab is hidden and no frames are drawn until you press Start again.

More in Device tests

All tools in this category: Device tests ·Updated November 3, 2026

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