How to Interleave PDF Pages
Interleaving combines two PDFs by alternating their pages — one page from File A, then one page from File B, repeating through both documents. This is commonly needed when you've scanned a double-sided document using a single-sided scanner, producing separate files for front and back pages. Interleaving merges them into the correct reading order. It's also useful for combining question sheets with answer sheets or matching bilingual document pairs.
Follow the step-by-step instructions below, then use the free tool directly — no registration or download required.
Open Tool →How to Interleave PDF Pages — Step by Step
Upload your two PDFs
Open the Interleave Pages tool and upload File A (typically the odd/front pages) and File B (typically the even/back pages). The tool displays page counts for both files.
Set the interleave pattern
Choose the default 1:1 pattern (A1, B1, A2, B2, ...) for standard double-sided reconstruction. For other use cases, set custom ratios like 2:1 (two pages from A, then one from B) if your document structure requires it.
Handle the back-page order
For scanner reconstructions, enable 'Reverse File B' if the backs were scanned in reverse order (last back page scanned first). This is common with automatic document feeders that flip the stack before the second pass.
Preview the interleaved result
Scroll through the merged preview to verify the page sequence. Check that page 1 front is followed by page 1 back, page 2 front by page 2 back, and so on. A single page out of order means the entire sequence shifts.
Download the merged document
Click 'Interleave' to produce the combined PDF. Download and verify by reading through a few page pairs to confirm the content flows correctly from front to back.
Pro Tips
- 💡 When scanning double-sided documents on a single-sided scanner, scan all front pages first in order, then flip the stack and scan all back pages. This makes interleaving straightforward.
- 💡 Always check whether your back-page scan is in forward or reverse order before interleaving. Getting this wrong produces a document that looks correct at first glance but has mismatched front-back pairs.
- 💡 If the two files have different page counts, the tool appends the extra pages from the longer file at the end. Add blank pages to the shorter file first if you need the interleave pattern to stay consistent.
- 💡 For bilingual documents (English/Spanish versions), interleaving creates a side-by-side comparison document that's useful for translation review.
Privacy & Security
All processing happens directly in your browser. Your files are never uploaded to any server — they remain on your device throughout the entire process. SublimePDF uses WebAssembly technology for fast, secure, client-side processing.
Works Everywhere
This tool works on any modern browser — Chrome, Firefox, Safari, or Edge — on desktop, tablet, or mobile. No software to install. PDF is an open ISO standard supported by all major platforms.
How to Interleave PDF Pages — FAQ
What if my two PDFs have different page counts?
Can I interleave more than two PDFs?
How do I know if I need to reverse File B?
Is interleaving the same as merging?
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