Ghosting Test — Spot Pixel Response Issues
A single object moving across your screen — pick the speed, pick the background, watch the trail. This is the simplest way to see whether your monitor's overdrive is set correctly or whether the panel is just slow.
A single object moving across the screen is the simplest way to see ghosting. Watch the trailing edge of the object — if you see a smudged after-image, your monitor's pixel response time is slower than the refresh interval. Higher speeds make the effect more obvious.
What ghosting actually is
Ghosting is the visible smear that trails a moving object on your screen. It happens because liquid crystal pixels take time to rotate from one colour to another — anywhere from 1 ms on a fast IPS gaming panel to 25 ms on a budget VA panel. While the pixel is mid-transition, it shows a mix of the old and new colours. Your eye, which integrates what it sees over about 80 ms, blends these intermediate states into a smear that follows the object.
The blur length is predictable. At 960 pixels per second on a 60 Hz monitor, the object moves 16 pixels per frame. If your pixels take 10 ms to transition, the smear is roughly one extra frame wide — about 16 pixels of visible blur. Faster pixel response means shorter smear; slower response means longer smear. Higher refresh rate also means shorter smear, because each frame moves the object a shorter distance.
The three things that cause ghosting
| Cause | What it looks like | How to fix |
|---|---|---|
| Slow pixel response (no overdrive) | Dark, even smear behind the object. Worse at higher speeds. | Enable overdrive in your monitor OSD. Start at Normal or Medium. |
| Overdrive too aggressive (overshoot) | Bright or coloured halo in front of the object — looks like a comet tail. | Lower overdrive to a softer setting. If still visible, disable overdrive. |
| Slow pixel response even with overdrive maxed | Persistent dark smear regardless of settings. | Your panel is the bottleneck. Consider a faster IPS or an OLED monitor. |
How overdrive works (and when it backfires)
Overdrive (also called Response Time, OD, or RT in monitor menus) pushes extra voltage through the liquid crystal to make it rotate faster. A well-tuned overdrive setting can cut response time in half with no side effects. A badly-tuned one causes overshoot — the pixel rotates past the target colour and bounces back, creating a bright or coloured halo around moving objects.
The right overdrive setting depends on your refresh rate. What works at 60 Hz might overshoot at 144 Hz. Many modern monitors handle this automatically with a variable overdrive feature (sometimes called Adaptive Overdrive), but most still require manual tuning. The general rule: pick the lowest overdrive setting that produces no visible smear on the ghosting test. Anything higher causes overshoot without further reducing blur.
VA panels and the smearing problem
VA (Vertical Alignment) panels are popular in budget gaming monitors because they offer deep blacks and high contrast. But VA panels have a known issue: transitions from very dark to mid-tone pixels can take 20–30 ms, far longer than the spec sheet suggests. In dark games with bright UI elements (CS:GO, Valorant, Apex Legends), this creates a distinctive black smear behind moving objects that no overdrive setting can fully fix.
If our ghosting test shows heavy black smearing on the black background, you are likely on a VA panel and there is no software fix. The next monitor to consider is a fast IPS (which trades contrast for response time) or an OLED (which has perfect pixel response at the cost of price and burn-in risk).
Frequently asked questions
More display tests
UFO Test
Visual motion blur test with multiple UFOs at different speeds.
Refresh Rate Test
Measure your monitor's actual Hz, not just what the OS reports.
FPS Test
Real-time browser FPS counter with frame-time histogram.
Frame Skip Test
Vertical colour bars for catching dropped frames with a camera.
Dead Pixel Test
Full-screen colour cycle to spot dead, stuck or hot pixels.
Input Lag Test
Estimate display + input latency with a click-to-flash reaction test.