How to Document Graphics Glitches Before Diagnosing a GPU Fault
Reproduce visual problems, distinguish intentional procedural effects from glitches, and collect screenshots and conditions for investigation.
An unexpected pattern on screen can come from application code, a driver, a display connection, or hardware. A browser screenshot alone does not identify its cause. The useful first step is to describe and reproduce the symptom under known conditions.
Know what the scene is supposed to do
Our shader demonstrations deliberately generate moving procedural patterns. Changing shader code can change the image or produce a compilation error. Do not label every unusual color as an artifact. Restore the original shader, camera, and settings before comparing an unexpected result.
For the shadow mapping test, shadow-map resolution and filtering influence jagged edges and shadow appearance. Those differences can be expected consequences of a setting, not a damaged card.
Capture a repeatable observation
- Record the page, browser and OS versions, viewport, and settings.
- Describe whether the problem is flicker, missing geometry, a frozen canvas, incorrect colors, or a complete display interruption.
- Capture a screenshot if possible and note when it occurred.
- Repeat at lower settings after closing competing applications.
- Compare another browser and another application before drawing a hardware conclusion.
Do not keep escalating the workload after a crash or unexpected glitch. Save the evidence and stop the test.
Separate image evidence from display evidence
If a screenshot captures the error, the problem exists in at least part of the rendered output. If it does not, that alone does not prove a cable fault; screenshot timing and overlays can also matter. Compare observations carefully and retain uncertainty.
A WebGL context loss can leave a blank canvas after resource pressure or a driver reset. Record console errors. Browser API or driver behavior may explain it without requiring a physical memory defect.
Understand the memory check's limit
The texture readback check compares sampled bytes from two reads. It does not verify every physical VRAM cell. A zero mismatch result cannot clear a card of all memory problems, and a reported mismatch needs reproduction and further investigation.
For persistent faults at ordinary settings, consult the device or application manufacturer's troubleshooting guidance. Avoid voltage changes or invasive repairs based solely on one browser observation.
Send a reproducible site problem through our contact page. The WebGL context-loss documentation explains the browser event.