Alternate & Mix
Interleave pages from two PDFs, e.g. front/back scanned sheets.
- 100% Private
- No Limits
- Works Offline
or drag and drop here
Interleave pages from two PDF files into a single combined document. Perfect for collating double-sided documents after scanning front and back pages in separate batches, with everything running safely in your browser.
How to Use Alternate & Mix
- 1
Upload both PDFs
Add the two documents you want to alternate. The first file provides odd pages and the second provides even pages.
- 2
Check order and options
Review the sequence preview, swap files if needed, and turn on 'Reverse 2nd file' if your back pages were scanned in reverse order.
- 3
Mix and download
Click Mix PDFs to interleave the pages into a single document instantly — no files are uploaded to any server.
Why Choose PurePDF for Alternate & Mix
Nothing leaves your device
Page mixing happens locally inside your browser via WebAssembly, keeping personal scans private.
Handles uneven page counts
If one document has more pages than the other, remaining pages are appended automatically in order.
Saves manual collating
Eliminates tedious manual page sorting after simplex scanner runs.
Common Use Cases for Alternate & Mix
Duplex scan merging
Combine front and back scans into correct order, even when back pages come out of the feeder in reverse order.
Bilingual documents
Alternate between two language versions of the same contract or presentation slide-by-slide.
Exam and answer sheets
Interleave test questions with reference sheets or answer keys.
Pro Tips for Alternate & Mix
- Check the sequence preview (e.g. 1A, 1B, 2A, 2B) to confirm the order, and enable 'Reverse 2nd file' if back pages were scanned backwards.
- Make sure the file with page 1 is placed in the top slot before running the mix.
- Run through Page Numbers afterward if you want fresh sequential numbering across the mixed file.
Frequently Asked Questions About Alternate & Mix
Will my PDF file be uploaded to a server?
No — nothing is uploaded. This tool runs entirely in your browser via WebAssembly/JavaScript; your file never leaves your device.
Is there a file-size limit, a usage cap, or a hidden fee?
It's free and unlimited, with no watermark and no forced file-size cap — the only real limit is your own device's memory for very large files.
Do I need to create an account or sign up?
No — no account, email, or sign-up is required for any tool. Just start using it.
Can I use this on my phone (iPhone or Android)?
Yes — it works in any modern mobile browser, no app install needed.
What happens if one document has more pages than the other?
If one document has more pages than the other, remaining pages are appended automatically in order.
How do I handle back pages that were scanned in reverse order?
Check the sequence preview to confirm the order, and enable 'Reverse 2nd file' if the back pages were scanned backwards.