Advanced Features
Keyboard Shortcuts
| Key | Action |
|---|---|
→ or Space | Advance to next color/gradient |
← | Go back to previous color/gradient |
Escape | Stop test and exit fullscreen |
Shortcuts work while the test overlay is focused.
Gradient Test Patterns
The gradient mode includes eight patterns designed to expose different display issues:
| Pattern | What It Tests |
|---|---|
| Horizontal B/W | Vertical banding |
| Vertical B/W | Horizontal banding |
| Horizontal R→G, G→B, B→R | Subpixel channel defects |
| Diagonal Gray | Corner-to-corner uniformity |
| Horizontal / Vertical Gray | Mid-tone banding |
Use gradient tests after color tests to confirm whether a defect is a true dead pixel or a color-reproduction issue.
Pixel Marking Logic
The tool classifies marks based on the current background:
- Dead pixel — marked on black backgrounds (pixel stays lit when it should be off)
- Stuck pixel — marked on colored or white backgrounds (pixel shows wrong color)
Marks within 5 px of each other are treated as the same pixel to avoid duplicates.
History Records
When a test finds issues, results are saved to local history with:
- Test mode (color or gradient)
- Dead and stuck pixel counts
- Full marked-pixel coordinates
- Timestamp
Load a previous record to review marks, or delete individual entries.
Report Export Format
Exported JSON reports include:
{
"timestamp": "2026-06-30T12:00:00.000Z",
"testMode": "color",
"results": {
"deadPixels": 1,
"stuckPixels": 0,
"totalIssues": 1
},
"markedPixels": {
"dead": [{ "x": 960, "y": 540, "color": "#000000" }],
"stuck": []
}
}
Attach this file to warranty claims or share it with a technician.
Multi-Monitor Testing
The tool tests the display where the browser window is shown. To test additional monitors:
- Move the browser window to the target monitor
- Run the fullscreen test
- Repeat for each display
Fullscreen Exit Behavior
Exiting fullscreen (e.g., pressing F11 or using the OS gesture) automatically stops the test and saves results if issues were found.