PDF page reorder

Common reasons people rearrange PDFs:

• Cleaning up a scan — a sheet-fed scanner sometimes grabs pages out of order or includes a blank divider. Drop the scan here, delete blanks, drag pages back into order.
• Merging selectively — extract just the pages you need from a long report. Combine with the merger to build a new document from several sources.
• Putting a cover page first — re-order a programme so the title page lands where it should.
• Splitting a duplex scan into the right order — feed-only scans of a stapled document often need every other page reversed.

Every thumbnail has four actions:

• ↑ / ↓ — move the page one slot earlier or later.
• Rotate — adds 90° clockwise. Press up to four times to come back to the original orientation.
• Delete — removes the page from the output document. The original file on disk is untouched.
• Drag — pick up a thumbnail and drop it before another one to move it. (Mobile users can use ↑ / ↓ instead.)

pdf.js renders a small JPEG of every page on a canvas, which you see as the thumbnail grid. When you click Apply, pdf-lib opens the original PDF, calls copyPages() in the new order, applies per-page rotations, and saves a fresh PDF. Page content streams are cloned byte-for-byte, so quality is identical to the source.

Both thumbnail rendering and the final rewrite happen entirely in your browser. The PDF bytes are passed between the React UI and a Web Worker; nothing is uploaded, logged or cached on a server.