Who operates ScreenMotion Lab
ScreenMotion Lab is an independent project operated by JHVL in Stockholm, Sweden. It is not affiliated with a monitor, television, phone or graphics-card manufacturer. The project brings together free browser tools and explanatory guides so that visitors can investigate a display problem and understand the limits of what they observe.
Why the site exists
A specification sheet cannot show whether a particular setting makes text harder to read or leaves a distracting trail behind a moving object. Opening a simple pattern provides a practical starting point. ScreenMotion Lab is intended for quick checks, comparisons between settings and learning about display behavior, without requiring a desktop application or an account for the core tests.
The tools answer different questions. Solid colors help you inspect pixels; gray fields make uneven patches easier to notice; motion comparisons show the effect of different update targets. A useful result may be a careful observation rather than a number. A patch that stays near one edge when you move your head suggests a different follow-up from a glow that changes with your viewing angle.
How the tools work
The test interfaces use standard browser technologies, including HTML, CSS, JavaScript, canvas drawing and video playback. Browser-reported information and software timestamps are available to these tools; direct measurements of light leaving the panel are not. A browser, operating system, graphics driver, display setting or room condition can affect the outcome.
For example, a motion lane with a high FPS target does not prove that a screen presents that many distinct frames each second. The page can count its updates, but that is different from measuring the panel. Likewise, the touch tool estimates software timing around input and animation callbacks. It cannot separate touchscreen hardware latency, operating-system processing and the moment the panel emits light.
Development and review
The source project contains automated checks for selected controls, calculations and animation behavior. These include simulated animation callback schedules for the FPS Comparison comparison and checks of pause, reset and offscreen behavior. Other checks exercise selected test controls and fullscreen fallback behavior. Such checks can catch implementation mistakes; a simulated schedule is not evidence that a physical monitor was tested at that refresh rate.
Content review compares explanations with the implemented behavior: what a control changes, where a reported value comes from and which conclusions the result supports. Guides should distinguish a visual pattern from a calibrated measurement. Corrections should address the specific claim or instruction rather than hide uncertainty behind a more precise-looking number. No list of tested devices, certification or laboratory validation is implied by these development checks.
What the results can and cannot establish
Use the patterns to compare conditions you can reproduce. Keep the same viewing position and room lighting, note the settings you changed and repeat the observation. A dark patch visible on one gray level, for example, is worth checking on another field before deciding it is a panel defect. Reflections, viewing angle and brightness settings may change its appearance.
ScreenMotion Lab cannot certify refresh rate, HDR performance, color accuracy, contrast ratio or input latency. Ordinary browser color steps are not a calibrated HDR signal or a measurement in nits. Pixel checks cannot guarantee that every dead or stuck pixel will be found, and displaying patterns does not guarantee a repair. When a decision requires measured performance or warranty assessment, use suitable measurement equipment or the manufacturer's support procedure.
Feedback and corrections
For a broken control, unexpected result or unclear explanation, use the contact page. Include the page address, device, operating system, browser version and the steps needed to reproduce the issue. State what you expected and what actually happened. If possible, describe whether the issue persists after reloading and whether fullscreen changes it.
For a factual correction, identify the sentence and explain the concern; a relevant primary reference helps distinguish an error from a limitation of browser testing. Reports provide a starting point for investigation, not a promise of a particular diagnosis or response time. The aim is to keep instructions useful, acknowledge uncertainty and correct claims that the tools cannot support.