High-refresh monitors can look wrong in a way that is hard to explain. The game says 144 FPS, Windows says 144Hz, but motion still jumps. Is the browser dropping animation frames? Is the GPU stalling? Is the monitor actually skipping physical refreshes?
I published the full guide on KeyboardTester.click with the live test, camera-confirmation workflow, source links, FAQ schema, and localized versions:
Frame Skipping Test: Check Dropped Frames on 144Hz and 240Hz
This Dev.to version keeps the practical test-then-confirm workflow.
Fast answer
A browser frame skipping test is a good first check for dropped animation frames, timing spikes, and unstable high-refresh motion. But it does not by itself prove that the physical LCD/OLED panel skipped a refresh.
For monitor-level proof, run the pattern full screen and take a phone/camera photo with enough exposure to capture several refreshes. A continuous sequence is healthy. Repeating gaps suggest skipped refreshes.
Start here:
Why screenshots do not prove frame skipping
A screenshot captures the rendered frame buffer. It does not capture what your display physically refreshed over time.
That is why a screenshot can look perfect even when motion feels choppy. The monitor might have shown, repeated, or skipped refreshes between the moments a screenshot can represent.
If you need evidence of physical monitor frame skipping - for example after a monitor overclock, new cable, used monitor purchase, or unstable 165Hz/240Hz mode - use a camera photo of the running pattern instead.
Browser dropped frames vs monitor frame skipping
These are related, but they are not the same problem.
| Symptom | What it usually means | Best next check |
|---|---|---|
| Browser test shows timing gaps | Browser, GPU, power mode, extension, or system load missed animation frames | Retest in a foreground tab, close load, try a second browser |
| Camera photo shows repeated blank gaps | Possible physical monitor refresh skipping | Lower refresh/overclock, test cable/port, retake photos |
| FPS average is high but motion feels bad | Frame pacing or 1% lows may be poor | Use an FPS/frame-time test |
| Motion smears but cadence is steady | Pixel response/overdrive issue, not skipped frames | Use a ghosting test |
| Expected 144Hz but test reads 60Hz | OS/GPU/monitor is set to the wrong refresh rate | Use a refresh rate test |
The main mistake is treating one browser spike as proof the monitor is bad. Browser tests are sensitive to background tabs, hardware acceleration, extensions, screen recording, remote desktop, battery saver, and thermal throttling.
How to run the first browser test
- Open the frame skipping test.
- Set the monitor to the refresh rate you actually use: 60Hz, 144Hz, 165Hz, 240Hz, etc.
- Keep the tab in the foreground and go full screen.
- Close screen recorders, heavy downloads, remote desktop sessions, and overlay extensions.
- Let the test run for at least 20-30 seconds.
- If it looks bad, repeat in another browser before blaming the panel.
On a stable display path, frame intervals should cluster near the expected refresh interval:
- 60Hz: about 16.67 ms
- 144Hz: about 6.94 ms
- 240Hz: about 4.17 ms
A much larger timing gap means something missed a frame in the browser animation path. It may be the browser or PC. It may not be the monitor.
How to confirm physical monitor skipping
Use the old but still useful camera method:
- Run the skipping pattern full screen.
- Keep the camera still.
- Use a shutter/exposure long enough to capture several refresh blocks in one photo.
- Take two or three photos, not one.
- Look for a repeating pattern of gaps.
At 144Hz, each refresh is only about 6.94ms. A photo capturing roughly one tenth of a second can contain around 14 or 15 refreshes. The exact count matters less than continuity. Regular spacing is good. Repeating blank slots are the warning sign.
Fixes if 144Hz, 165Hz, or 240Hz skips
Start with reversible changes:
- Confirm Windows/macOS and the GPU control panel both show the intended refresh rate.
- Turn off monitor overclocking or reduce the refresh rate one step, then retest.
- Temporarily disable VRR/G-Sync/FreeSync for isolation, then enable it again after testing.
- Update the GPU driver and restart.
- Try another certified cable if the issue appears only at high resolution plus high refresh.
- Avoid low-quality adapters when testing.
- Use a second browser for browser timing spikes.
If 165Hz skips but 144Hz is clean, use 144Hz for reliability. Some panels expose higher refresh modes that are not stable on every unit.
Helpful related checks
- Frame Skipping Test - dropped animation frames and timing gaps.
- FPS Test - browser animation rate and stability.
- Refresh Rate Test - confirm the display is really running at the expected Hz.
- Monitor Ghosting Test - separate skipped frames from pixel response blur.
Bottom line
Use the browser test first because it is fast. Treat it as a timing diagnostic, not a final verdict on the monitor.
If the result matters, confirm physical frame skipping with a camera photo of the running pattern. Then change one variable at a time: refresh rate, overclock, VRR, cable/port, driver, browser, and background load.
