Response Time Test
Track the moving objects in the UFO motion test and look for trailing or ghosting, then check the black-white transition boxes and scrolling text tests for smearing and blur. Run the bandwidth calculator before purchasing a cable to confirm it can carry the bandwidth your monitor and GPU require.
UFO Motion Test
Track the moving object with your eyes. Look for trailing/ghosting behind the object.
Black-White Transition Test
Tests pixel transition between extreme colors. Slow transitions indicate high response time.
Scrolling Text Clarity
Text should remain readable while scrolling. Blur indicates response time issues.
Response Time Guide
| Response Time | Rating | Best For |
|---|---|---|
| 1ms | Competitive gaming, fast-paced FPS | |
| 2-4ms | Gaming, action movies | |
| 5-8ms | Casual gaming, general use | |
| 10ms+ | Office work, static content |
Fast-moving objects that leave a smeared trail, text that blurs mid-scroll, or a ghostly outline chasing every color change — that's monitor ghosting, and it's caused by slow pixel response time. This response time test gives you three ways to see it directly: a moving UFO motion test that reveals trailing behind fast objects, a black-white transition test that isolates how quickly individual pixels switch between colors, and a scrolling text test that shows how ghosting affects real-world content like a webpage or a game HUD. Together they give you a fast, visual read on whether your display is fast enough for competitive gaming, action movies, or fast-scrolling content — no extra hardware required.
Why Monitor Response Time Matters and What Ghosting Looks Like
Every pixel on an LCD or OLED panel needs a finite amount of time to shift from one color to another. That interval is the panel's response time, usually measured in milliseconds (ms) and most commonly reported as gray-to-gray (GtG) — how long a pixel takes to move between two shades of gray. When response time is slow relative to how fast content moves across the screen, the eye perceives a trailing copy of the moving object: ghosting. The slower the pixel transition, the longer and more visible the trail. Use the monitor color test to check whether your display reproduces smooth gradients and accurate primary colours.
GtG vs. MPRT: Two Different Response Time Numbers
Manufacturers advertise GtG response time because it's the smallest, most flattering number — modern gaming monitors claim 1ms GtG routinely. But the number that actually predicts how blurry motion looks is MPRT (Moving Picture Response Time) — how long each frame stays visible on screen, which is tied to refresh rate and backlight strobing as much as pixel speed. A panel can have a fast GtG spec and still show visible motion blur if its MPRT is high, which is exactly why a visual test like this one is more useful day-to-day than trusting the number on the box.
Ghosting, Smearing, and Overshoot: What You're Looking For
Three distinct artifacts show up in response-time testing, and it helps to know them apart:
- Ghosting / trailing — a faint duplicate of a moving object lagging behind it, caused by pixels that haven't finished transitioning before the next frame arrives.
- Smearing — a smudged, low-contrast blur along the edges of moving text or shapes, most visible with light content moving over a dark background or vice versa.
- Overshoot / inverse ghosting — a bright or dark halo (sometimes called a "corona") around a moving object, caused by the panel's overdrive circuitry overcorrecting the pixel transition. This is a sign the response time is being artificially forced faster than the panel can cleanly handle.
Who Should Run a Response Time Test
Competitive gamers care most directly — in a fast-paced shooter or racer, a trailing ghost image behind an enemy or a track edge can cost a fraction of a second that matters. Anyone who watches fast action content, sports, or scrolls dense text-heavy pages (spreadsheets, code, long articles) will also notice smeared or blurred motion on a slow panel. And if you're shopping for a new monitor or TV, running this test against the display's advertised response-time and refresh-rate specs is the fastest way to confirm the marketing number matches what you actually see.
How to Run the Response Time Test and Read Your Results
Each of the three tests below isolates a different kind of motion, so it's worth running all three rather than relying on just one. You can test your refresh rate without any software by using the browser-based measurement tool directly.
UFO Motion Test: Reading Trailing and Ghost Images
Three rows scroll a moving object across the screen at an adjustable speed (Slow / Normal / Fast, or a custom pixels-per-second value on the slider). Track the object with your eyes as it crosses the track. On a fast panel, the shape stays crisp with a clean edge. On a slower panel, you'll see a fading trail behind it — the longer and more visible the trail, the higher the effective response time. Increase the speed to make ghosting more obvious, or slow it down to check for subtler smearing.
Black-White Transition Test: Spotting Slow Pixel Transitions
This test isolates the pixel transition itself rather than motion across the screen. Four boxes flash between color pairs — black↔white (the largest possible jump, and usually the slowest transition on any panel), gray↔gray (the GtG measurement manufacturers quote), black↔gray, and white↔gray — at a transition speed you control from 1Hz up to 60Hz. At low frequencies, watch for a visible flash lag or streak as the box changes; a fast panel snaps cleanly between colors, while a slow one shows a soft fade. Push the frequency up toward 60Hz to see whether the transitions can keep pace or start to blur together.
Scrolling Text Test: Real-World Blur Check
Fast motion tests are useful, but most of what you actually look at — a webpage, a document, a chat window — is text. This test scrolls a line of text continuously so you can judge legibility in motion rather than in a static frame. If the letters stay sharp while scrolling, response time isn't holding back everyday use. If the text turns into a blurred smear, that's the same pixel lag showing up in ordinary browsing, not just gaming.
This Is a Visual Test, Not a Precise ms Measurement
None of these three tests can hand you an exact "4.2ms" figure — that requires lab equipment like a photodiode oscilloscope rig or a high-speed camera measuring actual light output, the same methods independent reviewers use to produce verified response-time numbers. What this tool gives you instead is a fast, repeatable, and honest visual read: does ghosting look acceptable to your eyes, at the settings you actually use? That's often more useful than a spec-sheet number, since panel behavior varies with overdrive setting, refresh rate, and even the specific colors being transitioned.
Fixing Ghosting: Overdrive, Refresh Rate, and Panel Type
Overdrive / Response Time Settings in Your Monitor's OSD
Most gaming monitors expose a response-time or "overdrive" setting in the on-screen display, often labeled something like Off / Normal / Fast / Extreme (naming varies by brand). Overdrive works by overshooting the target voltage briefly to force pixels to transition faster than they naturally would. Run this test at each overdrive level to find the sweet spot — too low and you'll see ghosting; pushed too far and you'll see overshoot artifacts (the bright/dark halo mentioned above) instead. Most panels have one setting, usually the middle option, where ghosting is minimized without introducing visible overshoot.
Refresh Rate and Variable Refresh Rate (VRR) Interactions
Response time and refresh rate are related but separate specs — a refresh rate tester measures how many times per second the screen redraws, while this test measures how quickly each pixel can change color. A high refresh rate can't fix slow pixels, and a fast panel won't look smooth at a low refresh rate — you need both. Variable refresh rate technology (G-Sync, FreeSync) can also change a panel's effective overdrive behavior as the refresh rate fluctuates, which is why some monitors show more ghosting in VRR mode at certain frame rates than others. If you notice inconsistent ghosting during gameplay, it's worth retesting with VRR toggled on and off.
Panel Type and Response Time: TN vs IPS vs VA vs OLED
Panel technology sets the ceiling on how fast response time can get. TN panels have historically been fastest for GtG response, which is why they dominated budget gaming monitors for years. Modern IPS panels have closed most of that gap and now offer 1ms-class response times on gaming-focused models while keeping IPS's superior color and viewing angles. VA panels typically have the slowest GtG response time of the three LCD types, and are the most prone to visible dark-scene smearing — worth testing specifically if you're considering a VA panel for fast content. OLED panels respond essentially instantly at the pixel level (true sub-1ms GtG), which is why OLED displays show effectively zero ghosting in this test; any blur you perceive on OLED comes from MPRT/persistence rather than pixel transition speed.
| Response Time (GtG) | Typical Panel | What You'll See in This Test |
|---|---|---|
| <1ms | OLED, fast TN/IPS | Clean edges at all speeds, no visible trail |
| 1-4ms | Gaming-tier TN/IPS | Minimal trailing, only visible at fast UFO speeds |
| 5-8ms | Standard IPS/VA | Noticeable trail on fast objects, some scrolling-text blur |
| 10ms+ | Budget VA, older LCD | Clear ghosting on the UFO test, blurred scrolling text |
Frequently Asked Questions
- What is monitor response time?
- Monitor response time is how long a pixel takes to change from one color to another, usually measured in milliseconds (ms) as gray-to-gray, or GtG). A faster response time means pixels can keep up with fast motion without leaving a visible trail behind moving objects.
- What's the difference between response time and refresh rate?
- Refresh rate (measured in Hz) is how many times per second the screen redraws the whole image. Response time (measured in ms) is how quickly an individual pixel can change color. Both affect motion clarity, but they're independent specs — a high refresh rate can't compensate for slow pixels, and vice versa.
- What causes ghosting on a monitor?
- Ghosting happens when a pixel hasn't finished transitioning to its new color before the next frame is displayed, leaving a faint trailing copy of a moving object. It's most visible on panels with slow response times, especially during fast motion like scrolling text or fast-paced games.
- How do I fix screen ghosting?
- Most gaming monitors have an overdrive or 'response time' setting in the on-screen display (often labeled Off/Normal/Fast/Extreme). Increasing it speeds up pixel transitions and reduces ghosting — but setting it too high can introduce overshoot artifacts instead, so test a few levels with this tool to find the cleanest setting.
- What is overshoot or inverse ghosting?
- Overshoot happens when a monitor's overdrive circuitry overcorrects a pixel transition, creating a bright or dark halo around moving objects instead of a normal trailing blur. It's a sign the response time setting is pushed too aggressively for that panel.
- Can this test give me an exact response time in milliseconds?
- No — this is a visual test, not a lab measurement. Precise GtG and MPRT figures require specialized equipment like a photodiode oscilloscope rig. What this tool gives you is an honest, repeatable check of whether ghosting is visible at your actual settings, which is often more useful day-to-day than a spec-sheet number.
- Does OLED have ghosting?
- OLED panels have near-instant pixel response times (well under 1ms GtG), so they show effectively no ghosting in this test. Any motion blur perceived on OLED comes from MPRT (how long each frame stays lit) rather than slow pixel transitions.
- What response time is good for gaming?
- For competitive gaming, look for 1-4ms GtG response time, which shows minimal trailing even at fast motion speeds in this test. Casual gaming and general use are comfortable up to around 8ms, while anything above 10ms tends to show noticeable ghosting on fast content.