Frame Skip Test
The most advanced browser frame skip detector. 3 test patterns with real-time algorithmic frame drop detection, live frame time chart, and automated PASS/FAIL verdict — plus the traditional camera verification method.
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What is Frame Skipping?
Frame skipping occurs when your monitor receives frames from the GPU but fails to display every single one. Instead of rendering each refresh cycle, the display silently drops some frames, resulting in stuttery motion even if your FPS counter reports a high number. This is extremely common when overclocking monitors (e.g., forcing a 60Hz panel to run at 75Hz) — the scaler accepts the signal but cannot keep up.
Unlike low FPS (where the GPU sends fewer frames), frame skipping is a monitor-side issue. Your GPU is doing its job; the display is the bottleneck. A smooth 60Hz is always better than a stuttery 75Hz with frame skipping.
Why Our Test is Different
Traditional frame skip tests (including Blur Busters TestUFO and XbitLabs) rely entirely on the camera method — you need a phone with manual shutter control, a dark room, and the ability to interpret a photo. Our test provides two layers of verification:
- Algorithmic Detection (Instant) — We monitor the time between every
requestAnimationFramecallback. When the inter-frame delta exceeds 1.5× the expected frame time, we flag it as a dropped frame. This gives you a real-time verdict without any camera. - Camera Verification (Definitive) — The classic camera method is still available. Our numbered squares, column sweep, and color cycle patterns are all designed for easy camera analysis.
Understanding the Metrics
- Refresh Rate (Hz) — The detected rate at which your browser is delivering frames. Should match your monitor's refresh rate setting.
- Avg Frame Time (ms) — How many milliseconds each frame takes. At 60Hz this should be ~16.67ms, at 144Hz it should be ~6.94ms.
- Dropped Frames — Count of frames where the delivery time exceeded 1.5× the expected frame time.
- Jitter (σ) — Standard deviation of frame times. Lower is better. Values above 3ms may indicate instability.
- Consistency — Percentage of frames delivered within the acceptable timing window. 100% means zero drops.
Test Pattern Guide
- Numbered Squares: Displays cycling 0–9 digits that advance one square per frame. In a camera photo, missing numbers mean skipped frames. Easiest to interpret.
- Column Sweep: A single white column scans left-to-right across the grid. Produces a clean band in long-exposure photos — gaps in the band indicate skipping.
- Color Cycle: The active column cycles through 6 distinct colours. Missing colours in the photo confirm skipped frames. Useful if number analysis feels noisy.
Frequently Asked Questions
Is frame skipping dangerous for my monitor?
No, frame skipping won't damage your hardware. However, it defeats the purpose of running at a higher refresh rate. If detected, lower your Hz to the stable native rate for genuinely smoother motion.
Can a GPU cause frame skipping?
Rarely. Frame skipping is almost always a monitor/scaler limitation. GPU issues typically manifest as low FPS or stutter, not as dropped refresh cycles. If you see drops only in this test, it's likely a monitor or cable issue.
Why does the algorithmic method sometimes show drops even on a good monitor?
Browser-based timing can be affected by background tabs, OS scheduling, and GPU compositing overhead. If you see 1–2 drops over 30 seconds, it's normal browser jitter. 5+ drops or a consistency below 95% is a real concern — confirm with the camera method.
What shutter speed should I use for the camera method?
1/5th to 1/10th of a second. This captures enough consecutive frames to form a visible pattern. If your camera can't do manual exposure, take the photo in a very dark room — the phone will automatically slow down the shutter.
My monitor is not overclocked. Why should I test?
Even at stock rates, bad cables, outdated drivers, or power-saving modes can cause frame skipping. It's worth a quick 10-second test, especially on new monitors or after driver updates.