docstack

Arrange and merge PDF pages

Merge PDF files, privately.

Nothing is uploaded. Your PDFs are combined on this device, even with Wi‑Fi turned off.

or drop PDFs, images, PowerPoint or Word files anywhere on this page

Reorder · Rotate · Delete · Redact · Merge

Pages

0 pagesLong-press to select

Arrow keys move between pages. Shift with an arrow key extends the selection. Space or Enter opens a page. Alt with an arrow key moves the selected pages.

Combine PDF files into one

Add two PDFs or twenty and docstack lays out every page, grouped by the file it came from. You decide the order before anything is merged, and the files stay on your device.

  1. Add your PDFs

    Choose or drop the files you want to combine. Each one appears as a group of pages under its file name.

  2. Put them in order

    Drag pages where they belong, or use a file's menu to move its whole group to the start or the end. Delete the pages you do not need.

  3. Download the merged PDF

    Name the file and download it. Everything you arranged is written into one PDF.

What happens to your pages

Quality
Pages are copied into the new PDF as they are. Text stays selectable and images are not recompressed.
Page sizes
Every page keeps its own size, so A4, Letter and landscape pages can sit in the same file.
Adding more
Drop another file onto the pages and a line shows where it will land. You can also insert a file or a blank page between any two pages.
Protected PDFs
A password-protected PDF opens once you enter its password. Its pages are added as images, and docstack tells you before you download.
Other files
Images, PowerPoint and Word files can go into the same PDF.

Your files stay on your device

Many online PDF tools upload your files to a server to work on them. docstack does the work in this browser tab instead: files are opened, converted, arranged and merged on your device, and no file or page is sent anywhere. There are no analytics and no trackers.

You can check this yourself. Once the page has loaded, turn off Wi‑Fi and keep working: PDFs and images still open, rearrange and download.

There is one download to know about. The first time you add a PowerPoint or Word file, your browser fetches the tool that converts it (about 50 MB) from ZetaOffice. The file itself is still converted on your device.

Common questions

How many PDFs can I merge at once?

There is no set limit. Your files are held in your browser's memory, so how much it can handle depends on your device.

Does merging reduce quality?

No. Pages are copied as they are. The exceptions are pages you redact and pages from password-protected PDFs, which are saved as images.

Can I merge only some pages of a PDF?

Yes. Delete the pages you do not want before you download, or select the ones you do want and download only those.

Can I undo a mistake?

Yes. Every change can be undone and redone, including deleting pages.