ScreenCheckv1.0
motion
1–2 min
Client-Side Local

Observed Late-Frame & Drop Detection

Compares every requestAnimationFrame interval against the expected display refresh cadence to record observed late frames (>1.4x baseline) and severe pipeline stalls (>2.0x baseline).

Testing Instructions
  1. Allow the detector to establish a timing baseline for 60 frames.
  2. Watch the live counter of Observed Late Frames and Severe Stalls.
  3. Test system resilience by scrolling other windows or running background applications.
  4. Note: Classified honestly as "Observed Late Frames" inside the browser compositor.
Interaction Controls
Next Pattern
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Observed Late-Frame Cadence Telemetry

Observed Frames
0
Total sampled
Expected Cadence
16.67 ms
~60 Hz baseline
Observed Late Frames
0
> 23.3 ms (>1.4x)
Severe Stalls
0
> 33.3 ms (>2.0x)
Longest Hitch
16.7 ms
Peak delay
Terminology Notice: Results are designated as Observed Late Frames within the browser rendering loop. A late frame in JavaScript does not necessarily mean the physical monitor panel dropped a refresh cycle; it reflects timing delays within the browser process, GPU compositor, or OS scheduling.
Motion Controls
Velocity (px/s)
Motion Direction
Background Contrast

What This Test Checks

  • Observed late frames exceeding 1.4x the expected VSync interval.
  • Severe render stalls exceeding 2.0x the expected interval (true visual hitches).
  • Maximum single hitch duration in milliseconds.
  • Robust distinction between normal microsecond clock jitter and genuine missed frames.

How to Perform the Test

  • Allow the detector to establish a steady cadence baseline over at least 60 frames.
  • Watch the live counters for Observed Late Frames and Severe Stalls.
  • Try interacting with other open desktop windows to test your system’s background task resilience.
  • Click "Reset Cadence Counter" at any time to begin a fresh benchmark.

What to Look For

  • Zero stalls: High-performance graphics pipeline with zero dropped compositing ticks.
  • Minor late frames (1–2%): Normal web browser behavior when minor background tasks execute.
  • Severe stalls: Distinct visual hitching where the moving object visibly freezes for a fraction of a second.

Common Display Problems & Diagnostic Guidance

GPU Power-Saving Throttling

Laptops on battery power frequently throttle GPU clocks, causing periodic 50–100ms render stalls as clock states ramp up and down.

Browser Background Tab Throttling

All modern browsers reduce CPU/timer resolution down to 1Hz or pause rendering entirely when a tab is in the background to save battery.

Frequently Asked Questions

Does this test prove my physical monitor dropped a frame?

No. These metrics track "Observed Late Frames" inside the browser application environment. While this directly translates to perceived motion hitches on your screen, the physical monitor continues refreshing at its fixed hardware scan rate.

What is considered an acceptable late-frame rate?

For general web browsing, late frame rates under 1.5% are considered excellent. For competitive esports gaming monitors, 0% stalls during active testing is the desired standard.