Alternate & Mix
Mix pages from 2 or more documents, alternating between odd and even pages.
Tailored Parameters
Fine-tune exact dimensions, qualities, ranges, or security tokens for this feature.
Instant Local Processing
Zero latency local computation directly in your browser session.
Same-Page Workflow
Re-run operations repeatedly without losing your active tool workspace.
Alternate & Mix interleaves the pages of two or more documents instead of appending them end to end. Page one of the first file is followed by page one of the second, then page two of the first, and so on.
The situation this solves is almost always the same: a duplex document scanned on a single-sided feeder. You end up with one file holding the fronts and another holding the backs, often in reverse order. Interleaving reassembles the original.
How it works
- 1Add the two halves. Load the odd-page file first, then the even-page file.
- 2Reverse if needed. A stack of backs scanned in one pass usually comes out in reverse order; flip that file before mixing.
- 3Mix and check. Download the interleaved result and confirm that page two really is the back of page one.
When you need it
- Rebuilding a double-sided document scanned in two single-sided passes
- Interleaving a translation with its source text, page for page
- Alternating photographs with their captions or descriptions
Frequently asked questions
- What if the two files have different page counts?
- The shorter file simply runs out and the remaining pages of the longer one follow at the end. Nothing is discarded.
- Can I mix more than two files?
- Yes. Pages are taken from each document in turn, cycling through the list.
- Is this the same as merging?
- No. Merge appends whole documents one after another; this tool takes one page from each source in rotation.
- Are my documents uploaded anywhere?
- No. Every tool in PDF41 runs inside your browser tab using WebAssembly and JavaScript. Your file is read from disk into memory, processed locally, and handed back as a download. It is never transmitted to a server, so there is nothing to intercept, retain, or delete afterwards.
- Does this work without an internet connection?
- Yes, once the page has loaded. The PDF engine, fonts and character maps are all served from this site rather than a third-party CDN, so an unstable connection or a locked-down corporate network does not stop the tool from working.
Similar tools to use
Complete your document workflow with these frequently paired tools.
Merge PDF
Combine multiple PDF files and images into a single cohesive document.
Organize PDF
Visually sort, reorder, duplicate, delete, and rotate pages across files.
Split PDF
Split specific page ranges or extract each page into a separate document.