Frame Skipping Test
Check whether your display shows a fresh frame on every refresh, or quietly drops some. The test times each animation frame against your refresh rate and flags any that go missing — keep this tab focused for an accurate reading.
Live monitor running — keep this tab focused for an accurate reading.
Camera capture strip (optional)
A marker advances one box per rendered frame. Photograph the screen with a fast shutter or record in slow motion — a missing step reveals a dropped frame. Secondary to the detector above.
The browser paints once per display refresh, so the gap between frames should stay near one refresh interval — about 16.7 ms at 60 Hz or 6.9 ms at 144 Hz. This test times those gaps, takes the median as your true refresh rate, and flags any gap past roughly 1.5× the expected interval as a dropped frame, rounding to estimate how many were lost. Long pauses from switching tabs or minimizing the window are ignored, not counted as skips.
A dropped frame shows the previous image twice, so motion appears to jump. That is distinct from stutter (frames arriving at uneven intervals) and judder (the rhythmic unevenness of a frame rate that doesn’t divide cleanly into the refresh rate, like 24 fps film on a 60 Hz screen). This test targets true dropped frames — a clean run can still feel slightly off if pacing is uneven.
Common causes of frame skipping
| Cause | What’s happening |
|---|---|
| Cable or bandwidth limit | A high refresh rate at high resolution exceeds what the cable or port can carry — the classic cause of skipping only at the maximum rate. |
| Overclocked refresh rate | A panel pushed past its rated Hz looks stable but silently repeats frames instead of showing new ones. |
| GPU, driver, or thermals | Outdated drivers, an overloaded or overheating GPU, or aggressive power saving starve the display of finished frames. |
| Background load or throttling | Heavy work in other tabs, or the browser slowing frames for unfocused tabs, opens the gaps this test measures. |
This is a browser-level test of the presentation pipeline — display, cable, GPU output, driver, and browser — not of any game engine. It can’t see frames a game renders internally, measure input lag, or replace a hardware pattern generator. For the most reliable result, plug in a laptop, close heavy background tabs, keep this tab focused, and let a full timed run finish. The optional capture strip below photographs the screen with a fast shutter to reveal skips that are hard to feel.