Testing Methodology & Limitations

How it works: The test registers a continuous animation callback loop via window.requestAnimationFrame. Each frame receives a high-resolution DOMHighResTimeStamp from the browser. We record the delta interval (Δt = time - previousTime) across consecutive frames.

Mathematics: Over a rolling sample window (or during the 3-second diagnostic interval), the observed frequency is calculated as:

Nominal Frame Period: The nominal time allocated per frame is given by T = 1000 / Hz (e.g. 16.67ms at 60Hz, 6.94ms at 144Hz, 4.17ms at 240Hz). Note that frame period represents interval duration, not input latency or pixel response time.

Known Limitations: Background tasks, battery saver profiles, browser hardware acceleration toggles, and multi-monitor compositor pacing can cause the browser to present frames at a lower cadence than your panel's physical capability.

How it works: Renders configurable particle counts (from 1,000 to 20,000 entities) on an HTML5 2D Canvas context. Each particle calculates position, velocity, and collision bounds per frame.

Distinction from Hz: Frame Rate (FPS) is the count of unique frames your CPU and GPU calculate each second. Hz is how many times the screen displays an image. In a browser, requestAnimationFrame will typically cap canvas updates at the monitor's active refresh rate due to V-Sync. Under heavy particle load, FPS drops when computation time exceeds the frame budget.

How it works: Generates solid primary color fields (Pure Black, Pure White, Red, Green, Blue, Cyan, Magenta, Yellow) in full-screen mode.

Limitations: A web page cannot electronically probe individual transistor subpixels. This tool is a visual aid for human inspection to spot unlit (dead) or permanently lit (stuck) subpixels. The color-cycling stimulator rapidly alternates RGB values to attempt unstuck stimulation, but mechanical or manufacturing defects cannot be fixed by software.

How it works: An animated vertical bar sweeps horizontally at user-selected speeds. Screen tearing occurs when a new frame is sent mid-refresh, splitting the scanout.

Browser Context: Modern web browsers enforce compositor-level V-Sync. Screen tearing visible within the browser typically indicates an issue in windowed presentation or multi-GPU driver handshakes, rather than standard desktop tearing.

How it works: Moves high-contrast objects across varied background panels at calibrated pixel-per-second velocities to enable human pursuit tracking.

Important Scientific Distinction: Visual blur stems from two distinct physical sources:

• Pixel Response Time (GtG): How long physical liquid crystals take to transition. Slow transitions cause trailing behind moving objects. Fast-IPS and OLED reduce this significantly.
• Sample-and-Hold Retinal Persistence: How long each frame remains steadily lit on your retina while your eyes track motion. Even with a 0.03ms pixel response time, a 60Hz frame held for 16.67ms creates retinal blur. Higher refresh rates (144Hz, 240Hz, 540Hz) or backlight strobing directly reduce retinal persistence blur.

What it measures: End-to-end human cognitive reaction to an on-screen color transition, measured in milliseconds.

What it does NOT measure: This test does not isolate monitor input latency or click-to-photon latency. The recorded time combines human visual processing (typically 180–250ms), USB mouse input polling, operating system event dispatch, browser rendering delay, and monitor frame presentation.