Plugin: Thumbnail

Lazy thumbnail grid for visual page navigation.

The Thumbnail plugin renders a small bitmap of each page in a side-panel grid. Click any thumbnail to jump to that page.

Enabling flag

The Thumbnail plugin is always registered — useThumbnail is always available. features.thumbnails controls whether the thumbnails side panel is shown. It’s registered with { paddingY: 10 } so the first thumbnail clears the panel header.

What it does

Generates low-resolution previews of each page on demand
Lazy-loads — thumbnails render as they scroll into view, not all at once
Click navigation — clicking a thumbnail scrolls the main viewport to that page
The current page is highlighted in the grid
T keyboard shortcut to toggle the panel (when features.keyboardShortcuts is on)

Composable

useThumbnail(documentId) from @embedpdf/plugin-thumbnail/vue. Provides per-page thumbnail render hooks.

Events

None surfaced externally.

Dependencies

document-manager
render (to generate the bitmaps)
scroll (for click navigation)

Configuration

No featureConfig.

Performance note

Thumbnail generation is on a separate render path from the main viewport — generating thumbnails for a 500-page document is bounded by the lazy-load pattern (only visible thumbs are rendered). For 1000+ page documents, consider hiding the panel by default and only opening it on demand.