What if the PDFs have different lengths?

Pairs mode stops at the shorter one. All-pages mode appends the leftover pages from the longer document at the end.

Is there a page limit?

Mixed output caps at 100 pages to protect browser memory.

Alternate & Mix PDF Pages

This Alternate & Mix tool interleaves two PDFs page by page into a single downloadable document.

Mix pages from two PDFs by alternating them — page 1 from A, page 1 from B, page 2 from A — free in your browser.

About Alternate Mix

This Alternate & Mix tool interleaves two PDFs page by page into a single downloadable document.

Upload two PDFs. The mixer takes page 1 from A, page 1 from B, page 2 from A, and so on. Pairs mode stops when the shorter document runs out; otherwise leftover pages from the longer document are appended.

Processing uses the pdf-lib writer loaded from CDN, but your files never leave the browser.

Where it is used

Merging front/back scans, combining bilingual documents page by page, interleaving forms and attachments.

How to use the Alternate Mix

First PDF (odd positions) — select a file (application/pdf,.pdf) — PDF up to 50 MB. Files never leave your browser..
Second PDF (even positions) — select a file (application/pdf,.pdf) — PDF up to 50 MB..
Pages to Take — enter the value.
Calculate — press the Calculate button to see the result instantly above.

Formula

A1, B1, A2, B2, … until the longer document runs out (or pairs mode stops at the shorter).

Examples

Example

takeFrom:pairs

Result: Mixed PDF (after selecting two PDFs)

Frequently Asked Questions

What if the PDFs have different lengths?: Pairs mode stops at the shorter one. All-pages mode appends the leftover pages from the longer document at the end.
Is there a page limit?: Mixed output caps at 100 pages to protect browser memory.

Calculator Inputs