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.

How It Works

1

Upload the scan

Drop in the single PDF that holds all the front sides followed by all the back sides.

2

Set the split point

Mark where the front block ends, then choose whether the back block needs reversing.

3

Collate and download

Get one interleaved PDF, or a ZIP with a separate file per original document.

Related PDF Tools

Split PDF

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Merge PDF

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Alternate Merge

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Organize PDF

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Reverse Pages

Free online reverse pages tool

Extract Pages

Free online extract pages tool

Frequently Asked Questions

What if my scan has an odd number of pages?

A duplex scan should have an even page count. If it does not, a page was probably scanned twice or missed. The tool warns you before processing, and any unpaired pages are appended at the end so nothing is lost.

Why would I keep the back block as-is?

It depends on how the stack was fed for the second pass. Flipping the whole stack over produces back sides in reverse order, which is the default. If your scanner returned them in the same order as the fronts, choose to keep the block as-is.

Is ToolEasy really free?

Yes, absolutely. All tools on ToolEasy are 100% free to use, with no file limits, no sign-ups, and no watermarks. We believe everyone deserves access to simple, powerful PDF tools without a paywall.

Are my files secure? Where are they processed?

Your files are as secure as possible because they never leave your computer. All processing happens directly in your web browser (client-side). We never upload your files to a server, so you maintain complete privacy and control over your documents.

Does it work on Mac, Windows, and Mobile?

Yes! Since ToolEasy runs entirely in your browser, it works on any operating system with a modern web browser, including Windows, macOS, Linux, iOS, and Android.