docstack

Arrange and merge PDF pages

Merge PDFs offline, privately.

Open this page, then turn off Wi‑Fi. PDFs and images are still merged and arranged on this device.

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.

Merge PDFs with no internet connection

docstack is a web page that does its work on your device. Once it has loaded, it needs nothing more from the network for PDFs and images, so you can disconnect and keep working.

  1. Open docstack while online

    Load this page and give it a few seconds. The parts that read and write PDFs are fetched right after it opens.

  2. Go offline

    Turn off Wi‑Fi or unplug the cable. Keep this tab open, because opening the page again needs a connection.

  3. Merge and download

    Add PDFs and images, arrange the pages and download the result. The PDF is written by your browser, not fetched from a server.

What works without a connection

Works offline
Opening PDFs and images, reordering, rotating and deleting pages, inserting blank pages, redacting, and downloading the merged PDF.
Needs a connection
Loading the page in the first place, and converting PowerPoint and Word files.
Nothing to install
docstack is not a program you download. It runs in the browser you already have, with no account.
A way to check
A tool that keeps working with the connection off is not relying on a server to handle your files. It is a simple way to test a privacy claim yourself.

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

Do I need to install anything to merge PDFs offline?

No. Open docstack in your browser while you are online, then disconnect. There is no installer.

Can I open docstack with no connection at all?

Not the first time, and not after closing the tab. The page has to load once while you are online; after that it keeps working until you close it.

Is it slower offline?

No. The work was always done on your device, so the connection makes no difference to PDFs and images.

Can I convert Word files offline?

No. Converting PowerPoint and Word files needs a connection. PDFs and images do not.