Alternate & mix PDF
Interleave pages of two PDFs, like front and back scans. Runs on your device, nothing is uploaded.
How to use Alternate & mix PDF
- 01Drop two or more PDFs onto the upload area. They're labelled A, B, C in the order added.
- 02Tick Reverse on any file whose pages are in backwards order, such as the backs of a flipped scan.
- 03Choose how many pages to take from each file in turn; the result order is shown below.
- 04Click Download PDF.
A scanner that only scans one side leaves you with two files: all the front pages, then all the back pages, usually in reverse because the stack was flipped. Merging them puts every back page at the end. Alternating them puts each page back where it belongs: front 1, back 1, front 2, back 2.
Tick Reverse on the backs file and the tool reads it from the last page to the first, which matches how a flipped stack comes out. If one file is longer, its extra pages are added at the end once the shorter one runs out.
Taking 2 or 3 pages at a time is useful for mixing chapters or answer sheets. Pages are copied as they are with pdf-lib inside your browser, so quality doesn't change and nothing is uploaded.
Questions
Are my PDFs uploaded?
No. The pages are mixed inside your browser tab and nothing is sent to a server.
My back pages come out in the wrong order. What do I do?
Tick Reverse on the file with the back pages. A flipped stack is scanned last page first, and Reverse undoes that.
What if the files have different page counts?
Pages alternate until the shorter file runs out, then the rest of the longer file follows in order.
How is this different from Merge PDF?
Merge puts whole files one after another. This weaves their pages together.