Monitor Frame Skipping Test: Check Dropped Frames Online
Monitor Frame Skipping Test. Click Start to run this monitor frame skipping test and see whether your screen drops any frames. The monitor flicker test online is free and runs entirely client-side, so nothing about your display is ever uploaded.
Interactive Tool
Frame Skipping Test
Click Start and watch the counter and moving marker below — each tick should advance by exactly one frame. If the counter reports zero dropped frames but the panel still looks stuttery, dropped panel frames need the camera long-exposure method (photograph the moving marker with a shutter speed slower than one frame) to confirm the display itself is the cause, not your browser.
The Monitor Frame Skipping Test advances a numbered marker one step every animation frame and logs the gap between frames, so you can watch the Frames Rendered and Dropped (Browser-Side) counters while it runs. Click Start and let it run for a bit — your browser can only catch drops happening on its own side, so if the counter looks clean but playback still feels stuttery, the camera long-exposure method is the way to confirm whether the panel itself is skipping frames.
Is your monitor frame skipping test result the missing piece behind that odd hitch in motion? Use this free frame skipping test online to see whether your screen is holding a steady refresh rate, because skipped frames are logged as they happen in your browser, so a smooth-looking screen can finally be checked with numbers.
How the Monitor Frame Skipping Test Works
Every monitor redraws its screen a fixed number of times each second. A skipped frame happens when your browser misses one of those redraw deadlines, so the previous image stays up for an extra cycle. The test sets a moving bar in constant motion across a track and times every frame with the browser's animation clock, exposed through requestAnimationFrame, instead of a fixed timer. Nothing leaves your device. The free monitor black level test is free and runs entirely client-side, so nothing about your display is ever uploaded.
Frame Timing and Refresh Interval Detection
The test reads the gaps between frames and treats the shortest, steadiest gap as your refresh interval, so a 60Hz laptop screen and a 120Hz panel are both detected without any setting. A gap that stretches well past that interval is flagged in real time, which is the signal that a frame arrived late.
Skip Rate, Longest Stall and Jank Score
While it runs, a skip counter tracks frames rendered and frames skipped. When you stop, you get your skip rate as a percentage, the longest stall in milliseconds, and a plain-language jank score. A jank rating built on every frame catches single hitches that an average, like the one on a game's fps counter, would hide.
How to Run a Frame Skipping Test Online
Close other programs to protect performance, keep this tab in the foreground and follow three steps: Run the free subpixel test to check your display for this issue directly in your browser — no download required.
- Press Start so the bar begins moving.
- Watch the bar for red flashes while it runs for at least 30 seconds.
- Press Stop to read your score.
Start the Test and Watch for Red Flashes
Each red flash marks a missed deadline and matches one tick on the skip counter. Switching to another tab pauses rendering in the browser, which is why this video-style test needs to stay visible to give a fair result.
Stop the Test and Read Your Score
A clean run looks smooth, with a skip rate near zero. A run with frequent stutter shows a high skip rate and a long stall. Repeat the benchmark twice, because one run can be thrown off by a stray update.
Why a Gaming Monitor Shows a Frame Skip
Gaming at 144Hz or 240Hz leaves the machine only a few milliseconds per frame, so small delays turn into a visible hitch in a shooter or any fast game, and the test logs each one as a skipped frame with its stall length. The cause sits in the hardware chain, the software, or both. A battery-saving mode on a laptop can also hold the previous frame longer than expected.
GPU and CPU Stress Test Load, Plus Background Processes
If the GPU or CPU is busy, the browser finishes drawing late. A stress test, a video call, a download or too many background tabs and background processes all compete for the same time. Update the graphics driver and let the operating system finish its updates before you repeat the run.
Cables, Signal Integrity and Overclocked Refresh Rates
If skips continue with a quiet machine, look at the display link. A weak cable or poor signal integrity on DisplayPort can degrade a frame so the monitor repeats the previous frame. Non-standard refresh rates and an overclocked monitor make this more likely, and developers building VR hardware report the same symptom. A video capture card may resample frames, so it is a poor way to confirm the cause. This test also does not replace a dead pixel or ghosting check.
Checking a 165Hz Overclock: Skip Rate Before and After
Dana has just pushed a 144Hz monitor to 165Hz with a custom resolution and wants to know whether the extra 21Hz is real or just a number in the settings panel. Before trusting that setting, Dana closes every other tab and app, opens the dropped-frame test and lets the tally run for 60 seconds.
At 165Hz that is 165 × 60 = 9,900 frames. The counter finishes on 38 skipped frames, so the skip rate is 38 ÷ 9,900 = 0.38%, with a longest stall of 18.2 ms. Dividing 18.2 by the 6.06 ms interval (1000 ÷ 165) says three frames were held back to back, which is why the bar visibly hesitated twice near the right edge.
The skip rate looks tiny, and by the usual rule of thumb that skips under a few percent go unnoticed, it passes. The stall is what Dana decides on: three held frames in a row is exactly the hitch a competitive shooter player feels. As a cross-check, Dana repeats the run at the original 144Hz: 8,640 frames, 3 skipped, 0.03%, and a longest stall of one interval (6.94 ms).
| Setting | Frames | Skipped | Skip rate | Longest stall |
|---|---|---|---|---|
| 165Hz overclock | 9,900 | 38 | 0.38% | 18.2 ms |
| 144Hz stock | 8,640 | 3 | 0.03% | 6.9 ms |
The number to watch here is the stall, not the percentage: a rate ten times higher can still look smoother than a low rate made of one long freeze. Dana then tries 155Hz as a middle step and keeps whichever setting stays at single-frame stalls.
One caveat: this test reflects what the browser delivered on time, so a panel that repeats a frame on its own can slip past it. A camera-based check like TestUFO's photo method is the better second opinion.
Reading Skipped Frames by Refresh Rate
A skip costs more time at lower refresh rates because each interval is longer. Use this table to translate a stall in milliseconds into missed frames.
| Refresh rate | Frame interval | Frame skip of 3 frames |
|---|---|---|
| 60Hz | 16.67 ms | 50.0 ms |
| 120Hz | 8.33 ms | 25.0 ms |
| 144Hz | 6.94 ms | 20.8 ms |
| 240Hz | 4.17 ms | 12.5 ms |
Refresh Rate Worked Example on a 144Hz Display
Say you run the test for 30 seconds on a 144Hz screen. That is 30 × 144 = 4,320 frames, and the counter shows 52 skipped. The skip rate is 52 ÷ 4,320 = 1.2%. If the worst hold reads 41.7 ms, divide by the 6.94 ms interval to find about 6 frames were held at once.
Frequently Asked Questions
- What counts as a skipped frame?
- A skipped frame is a refresh the screen was due to show a new image for, but the previous frame stayed up for an extra cycle because the browser was late.
- How does the test know my refresh rate?
- It times the gaps between frames and treats the shortest, steadiest gap as the refresh interval, since a skip can only lengthen a gap. You can also enter the rate yourself here.
- Is a skip rate of 1% something to worry about?
- Usually not. Background tasks cause occasional skips on healthy hardware. Rates in the double digits, or long stalls of several frames in a row, deserve investigation.
- Why do I get more skips with other tabs open?
- Every tab and background app competes for the CPU and GPU time your browser needs to draw each frame on schedule, so video calls and downloads raise the skip rate.
- Does a browser test catch every kind of frame skipping?
- No. It shows whether your browser delivered frames on time. If the monitor itself repeats a frame, for example on an overclocked panel or a weak cable, a camera-based check is a better second opinion.
- Why does frame skipping matter more at higher refresh rates?
- At 144Hz or 240Hz each frame gets only a few milliseconds, so small delays are more likely, and they are easier to notice in fast games.