Rearrange PDF pages by dragging thumbnails — then save the new order

How to use the PDF page reorder tool

1. Drop a PDF onto the box or press Choose a file. Thumbnails of all pages appear in a grid. Each shows its current position.
2. Drag a thumbnail to a new place with the mouse, a finger or a pen. The other pages shift to make room. A moved page shows its new position and its old number, for example 2 (was 5).
3. To move a page one step, use the ← and → buttons under it, or focus it and press Alt + ← or Alt + →.
4. Press Reverse to flip the whole order, or Reset to go back to the original order.
5. Press Save new order and download the file, named with -reordered added (for example report-reordered.pdf).

What it does and when to use it

Pages end up in the wrong order more often than you would think:

• Scanning by hand. You scanned the pages of a form in the wrong order, or a sheet was fed in twice and came out of sequence.
• Merging files. After you merge several PDFs, the cover letter sits at the end and needs to move to the front.
• Changing a presentation. You want slide 9 to come before slide 4 for a different audience, but you only have the PDF.
• Assembling an application. A portal wants the ID page first, then the certificate, then the reference letter.

The visual grid is the point of this tool: you see each page, so you do not have to work out page numbers. If you already know the exact list of pages and want to drop some at the same time, the PDF page extractor takes a typed list such as 3, 1, 2, 4- instead.

How it works

The tool uses two libraries, both running in your browser:

• pdf.js (pdfjs-dist) draws the thumbnails. It parses the file in a background worker and only draws a thumbnail when it scrolls into view, so a 200-page file does not draw 200 pages at once. If the PDF uses standard fonts or character maps it does not include, pdf.js may download that data from cdn.jsdelivr.net. Your document is not sent anywhere.
• pdf-lib (@cantoo/pdf-lib) saves the new order. When you press Save new order, the grid’s order is passed to a background worker as a list like 3, 1, 2, 4, 5, …. pdf-lib rewrites the PDF’s page list in that order and saves the file.

Before rewriting the list, settings that pages can inherit from a parent (page size, rotation, fonts and other resources) are copied onto each page, so every page looks exactly as before. Objects that no longer belong to any page are dropped, which can make the saved file a little smaller.

Worked examples

These come from a 12-page A4 report, report.pdf.

Bring page 3 to the front. Drag the third thumbnail before the first. The grid now shows 1 (was 3), 2 (was 1), 3 (was 2) and pages 4 to 12 unchanged. Saving gives the summary New order: 3, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12 and a 12-page report-reordered.pdf.

A scan fed last page first. Press Reverse, then Save new order. The summary reads New order: 12, 11, 10, … 1. If you only ever need to reverse, the PDF page reverser does it without the grid.

Swap two slides. Focus thumbnail 4 and press Alt + → five times. Slide 4 moves to position 9 and the slides that were after it each move up one place.

Limits and tips

• Every page is kept. The grid can only move pages, not remove or copy them.
• Long orders are shortened in the summary. The line stops after about 120 characters, but the saved file has the full order.
• Very large files. Thumbnails and the save both need the whole file in memory. On phones, files of several hundred megabytes may not open.
• Password-protected files must be unlocked first with Unlock PDF, using the password you know.
• Rotated pages keep their rotation. To turn a page the right way up, use the PDF rotate page range tool before or after reordering.
• Check the result. Open the saved file in the PDF viewer before you send it.