How to merge PDF files without uploading them

Merging PDFs offline is what File > Combine files in PDF by Zaweba is for. You put the files in a list, choose which pages of each to include, and the app joins them into one new document on your own computer, adding a bookmark for each file. Nothing is uploaded, and no account is needed.

Online merging sites are quick, but they mean sending your files to a server you know nothing about. For a mortgage application, a set of medical letters or a client's contracts, that's a real cost. Doing it on your own PC removes the question.

Building the list

Choose File > Combine files. Add the PDFs you want, either from your folders or from the documents you already have open in tabs. The list can be put in order by moving files up and down, sorted by name, and trimmed by removing anything added by mistake. If you'd find it easier to see what each file is, the files can be shown as thumbnails rather than names.

Each file in the list has its own page list. Leave it as all pages, or give a selection, so you can take the first three pages of one document, page seven of another and the whole of a third.

When you combine them, the result opens as a new document that hasn't been saved yet. Look through it and then save it under a name of your choosing. The original files are not touched.

What survives the merge

Cheap merging often flattens documents into pages and nothing else. PDF by Zaweba joins them object by object, so more of each file comes across intact.

Form fields stay interactive. If two files both have a field with the same name, they are either renamed (the second becomes name_2) or merged, so filling one doesn't unexpectedly fill another. Layers, links, named destinations and attachments are kept. Accessibility tags from the different files become one tag tree. And fonts and pictures shared between the files are stored once, not twice, which keeps the merged document smaller.

The bookmark per file is a small thing that makes a big difference in a long pack. Open the bookmarks panel and every original document is one click away.

Making a tidy combined file

Put the files in the order a reader will want before combining, rather than reordering pages afterwards. Name the files sensibly first, too, because sorting by name and the per-file bookmarks are both more useful when the names mean something.

Use the page lists to leave out cover sheets, blank pages and duplicate terms and conditions. If a pack is heading for an email, the file-size choice offered by Combine files helps keep it under an attachment limit, and File > Reduce file size can shrink it further afterwards.

Other page jobs offline

Merging is often one step in a bigger tidy-up. PDF by Zaweba can also split a document into parts, extract pages into a new file, delete and rotate pages, and drag thumbnails into a new order, all on your own computer.

PDF by Zaweba is free software for Windows, offline and with no account, so the papers you merge stay private from start to finish.