Open the popup (or the in-page panel via the toolbar icon) and try each mode against the boxes below. Element — click "Select Element" and hover any box. Area — drag a rectangle anywhere on the page. Screen — captures just what's visible right now. Page — captures this entire scrollable page, stitched together.
Fits entirely in the viewport — should always be a single capture, no stitching.
Taller than the viewport. With "Scroll Element" enabled in Settings, capture should scroll down and stitch tiles so every marker below appears in the result.
Wider than the viewport — exercises horizontal scroll + stitch.
Exceeds the viewport in both directions — verify all four corners and the center land in the final image.
This box has its own overflow: auto — its content is taller than the box
itself, separate from the page's scroll.
Hover each box above — the highlight should turn indigo/dashed when it exceeds the viewport.
Drag a rectangle spanning two boxes and confirm the crop lines up pixel-for-pixel.
Scroll partway down the page first — only the visible viewport should be captured.
Captures top to bottom of this whole page — check every marker above appears once, undistorted.