Combine PDFs and keep the links and bookmarks

You can combine PDFs and keep their bookmarks and links with PDF, the free PDF app in Madosuite. Its Combine files tool merges any number of PDFs into one, gives each file a bookmark with its own bookmarks nested underneath, and rewires links to the copied pages.

It runs in a browser tab on your own computer. The files are not uploaded to us.

Why merged PDFs lose things

A PDF is more than its pages. A report can carry a bookmark outline, links from the contents page to each chapter, form fields, layers that switch on and off, and files attached inside it.

A merge has to carry each of those across and point it at the right page in the new file. A link that pointed to page 4 of the second file now has to point to, say, page 31 of the combined one. If a tool only copies what each page looks like, the pages arrive and the rest is left behind: the outline is gone, links do nothing, and form fields turn into flat pictures of boxes.

What PDF keeps when it combines

The app’s developers list these as kept when you combine, extract or split:

• Bookmarks. Each source file gets a bookmark, with its own bookmarks nested underneath.
• Links and named destinations, rewired to the copied pages.
• Form fields, which stay interactive.
• Layers, which keep their on and off defaults.
• Attachments, which come along.

Every page of a combined document renders the same as it did in its source file, pixel for pixel.

Combine the files

1. Go to the Madosuite desktop. No account is needed.
2. Open Files, press Upload and pick the PDFs you want to combine. You can upload them one after another.
3. Open PDF and choose Combine files. The quickest way is the command palette: press Cmd-K and type “combine”.
4. Choose the PDFs to combine. Think about the order first, because it sets the order of the pages and of the bookmarks.
5. Combine them, then save the result as a new PDF.
6. Open Files and download the combined file.

If a source file is password protected, PDF can open it once you enter the password. Edits to an encrypted document are saved encrypted, under the same keys.

Tidy the result

Once the files are together, you may want to change the page order or drop a page. Open Organize pages to see every page at once as thumbnails. Select pages with a click, Cmd-click or Shift-click, then rotate, delete, insert blank pages, insert pages from another file, or move them earlier or later.

Every change is one step in the undo history, and the Edit menu names the step, such as “Undo Rotate pages”. Undo still works after you save.

Check what came through

Before you send the combined file, spend a minute on it:

1. Bookmarks. Open the Bookmarks panel. You should see one entry per source file, with each file’s own outline nested inside. You can search bookmark titles to find a nested entry.
2. Links. Click a few links in the contents pages. Each should land on the right page in the new file.
3. Forms. If a source had form fields, click into one and type. It should still accept input.
4. Layers. If a source had layers, switch them on and off in the Layers panel.
5. Attachments. Check that attached files can still be opened or saved.
6. Page labels. PDF shows a document’s own page labels (i, ii, 1, 2 and so on), which helps you find your place in a long result.

Splitting and extracting work the same way

The same rules apply in reverse. Extract copies the pages you select into a new document. Split divides a document every so many pages, or before the pages you choose. Links, form fields, layers and attachments come along in both cases. See split a PDF and extract pages.

Limits

• PDF is alpha. That is the app’s own status. Organizing, combining and splitting are listed as good today, but check the result as above.
• No printing from the browser. The web build of the app cannot print. Download the combined file and print it elsewhere.
• Full XFA forms are listed as missing. Ordinary form fields are kept; an XFA form may not behave the same.
• Hostile files. The developers say fuzzing still finds crashes and hangs on deliberately broken files.
• Clearing the site’s data in your browser deletes the files in Madosuite’s home folder. Download the combined file when you are done.

PDF is one of the ArtCraft team’s open-source Crafting Apps (MIT or Apache-2.0), shipped in Madosuite under the name PDF.

For the quick version, go to merge PDFs, or see everything on the PDF app page.