How to Merge Odd Even Pages
Merging odd and even pages is the go-to solution when you've scanned a double-sided document in two passes — one pass for all odd pages (fronts) and another for all even pages (backs). This happens with single-sided scanners, flatbed scanners, and copiers that lack automatic duplex scanning. SublimePDF weaves the two separate files back into the correct alternating sequence to reconstruct the original document.
Follow the step-by-step instructions below, then use the free tool directly — no registration or download required.
Open Tool →How to Merge Odd Even Pages — Step by Step
Upload the odd-pages file
Open the Merge Odd/Even tool and upload the PDF containing all odd-numbered pages (1, 3, 5, 7...). This file should have pages in forward reading order.
Upload the even-pages file
Upload the second PDF containing all even-numbered pages (2, 4, 6, 8...). Check whether the even pages are in forward or reverse order — scanner behavior varies.
Set the even-page order
If the even pages are in reverse order (which is common when flipping a stack on the scanner), enable the 'Reverse even pages' toggle. The tool will reverse File B before interleaving.
Preview the merged result
The preview shows the reconstructed document with alternating pages from both files. Verify that page 1 (odd) is followed by page 2 (even), page 3 by page 4, and so on. Check several pairs throughout the document.
Download the complete document
Click 'Merge' to produce the fully reconstructed double-sided document. Download and verify the reading order is correct from beginning to end.
Pro Tips
- 💡 Label your scans immediately — name one file 'fronts.pdf' and the other 'backs.pdf' before you close the scanner software. Trying to figure out which is which later wastes time.
- 💡 If the merged result has mismatched page pairs (front of page 3 paired with back of page 5), the even-page file is likely in the wrong order. Try toggling the 'Reverse even pages' option.
- 💡 For documents with an odd total page count (e.g., 15 pages), the even-pages file will have one fewer page than the odd-pages file. The tool handles this automatically, placing the last odd page at the end.
- 💡 After merging, run the document through the Compress PDF tool — two-pass scanning often produces larger files than single-pass duplex because each pass compresses independently.
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 Merge Odd Even Pages — FAQ
What if the two files have different page counts?
How do I know if my even pages are in reverse order?
Can I use this tool for non-scanned documents?
Does this preserve the original page quality?
Related Guides
How to Merge PDF Files Online
Merging PDF files is one of the most common PDF tasks — whether you're combining reports, contracts, or scanned pages into a single document. SublimePDF lets you merge PDFs instantly in your browser with no file uploads to any server.
How to Merge PDF On Mac
macOS includes built-in PDF merging through Preview, making it one of the few operating systems where you can combine PDFs without extra software. However, Preview's approach has limitations—it modifies the original file, offers no compression, and doesn't support batch operations. For quick two-file merges, Preview is convenient. For anything more complex, SublimePDF's online tool provides reordering, selective page merging, and file size optimization.
How to Merge PDF On Windows
Windows doesn't include a native PDF merging tool—Microsoft Print to PDF can create PDFs but can't combine them. Most Windows users resort to paid software like Adobe Acrobat or random free tools bundled with adware. SublimePDF's web-based merge tool works in any Windows browser (Edge, Chrome, Firefox) with no installation, no ads, and no file size surprises. For power users, PowerShell and command-line options also exist.