Duplex Collate

Reorder a PDF scanned as two blocks (all fronts, then all backs) into proper front/back order.

Click to select a file or drag and drop

A single PDF file

Your files never leave your device.

About Duplex Collate

If you scanned all the fronts and then all the backs into one PDF, Duplex Collate rearranges the pages into proper double-sided order.

How to use it

Select your PDF, or drag it onto the drop area.
Confirm the batch layout.
Collate and download.

Your file stays on your device

This tool runs entirely in your browser. Your file is read from your device, processed in memory, and saved back to your device — it is never uploaded to Qpdf or anyone else. Once this page has loaded, the tool also works with your internet connection switched off.

How Qpdf keeps files private →

Good to know

Check the first few pages of the result to confirm the order before discarding the original scan.

Related tools

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Alternate & Mix Pages Merge PDFs by alternating pages from each file.

Reverse Pages Flip the page order of a document.

Reorder PDF Pages Drag pages into a new order, duplicate or remove them.