DOM windowing

Virtual grid for 1000 PDF pages

Only the visible viewport cards are rendered. Drag pages to reorder, rotate cards, and scroll quickly without flooding the DOM.

Virtual PDF page grid

1,000 pages · 4 columns · rendering 24 cards

Original page 1

Original page 2

Original page 3

Original page 4

Original page 5

Original page 6

Original page 7

Original page 8

Original page 9

Original page 10

Original page 11

Original page 12

Original page 13

Original page 14

Original page 15

Original page 16

Original page 17

Original page 18

Original page 19

Original page 20

Original page 21

Original page 22

Original page 23

Original page 24

Memory release checklist

Only viewport cards plus overscan are mounted; the 1000-page array remains lightweight metadata.
When using real PDF thumbnails, store preview URLs and call URL.revokeObjectURL(url) when closing the file.
Clear React state with setPages([]), terminate any pdf.js render tasks, and null large ArrayBuffer references.
For huge files, generate thumbnails lazily and keep a small LRU cache instead of holding 1000 full-resolution canvases.

User guide

How to use Virtual PDF Page Grid

Keep only visible page cards mounted while preserving page indices for sorting and rotation.

1
Load or generate the page list.
2
Scroll to confirm that only a buffered visible range is mounted.
3
Drag a visible card to reorder it; scroll when needed.
4
Commit the final order to the PDF-processing module.

Best for

Documents with hundreds of pages
Page sorting interfaces

Important limitation

HTML5 drag-and-drop has limited touch support; mobile devices may need pointer-based dragging for the best experience.

Frequently asked questions

Are off-screen pages deleted?

No. Their data stays in the array while their DOM cards are unmounted.

How is memory released?

Revoke preview URLs, clear page arrays and caches, cancel render tasks, and terminate Workers.

PDFPerch processes files locally unless this guide explicitly identifies a cloud-dependent feature. Always keep an original copy and verify critical output before submission, printing, signing, or accounting use.