everyday mac tools

Do the same thing to a whole folder of PDFs on a Mac

· 7 min read

Preview handles one PDF at a time, so a job like watermarking forty files means forty rounds of the same clicks. macOS has two built-in ways around that. Finder’s Quick Actions cover simple one-off jobs, such as combining a selection into one PDF. Automator can watermark, encrypt, compress or combine a whole selection in one go, and save the steps so you can run them again next month. Whichever you use, work on copies, check one result properly, and put any password step last.

Quick Actions in Finder for simple jobs

Finder has a few PDF jobs built in, and they work on many files at once:

  1. Select the PDFs (and any images you want included) in a Finder window.
  2. Control-click the selection and choose Quick Actions, then Create PDF.

Finder makes one combined PDF in the same folder and leaves the originals alone. Check the page order in the result. If it is not what you wanted, number the file names (01, 02, 03) and sort the window by name before you try again. Merge PDFs on a Mac without uploading them anywhere covers merging in more depth, including Preview’s sidebar method.

Customize, at the bottom of the Quick Actions submenu, shows which actions are switched on. Any Quick Action you build yourself, as below, appears in the same submenu.

Automator for repeatable batches

Automator is in the Applications folder. It strings together actions into a workflow, and it has a set of actions just for PDFs. Saving the workflow as a Quick Action puts it in Finder’s Control-click menu, which is the most convenient way to use it.

  1. Open Automator, click New Document and choose Quick Action.
  2. At the top of the workflow, set “Workflow receives current” to PDF files, in Finder.
  3. In the Library column on the left, click PDFs to see the PDF actions. These include Watermark PDF Documents, Encrypt PDF Documents, Apply Quartz Filter to PDF Documents (used for compression) and Combine PDF Pages.
  4. Drag the actions you want into the workflow area on the right, in the order they should run, and fill in their options.
  5. If Automator offers to add a Copy Finder Items action so your originals are not changed, accept it and choose a destination folder for the copies.
  6. Choose File, Save and give it a name you will recognize in a menu, such as “Watermark as Draft”.

To run it, select a batch of PDFs in Finder, Control-click, choose Quick Actions and pick your workflow. Automator can also save a workflow as a Folder Action, which runs on every file you drop into a chosen folder. That suits a job that never changes, such as compressing every scan that lands in a Scans folder.

Be realistic about what these actions can do. They are plain, older tools. Compression through a Quartz filter can make scanned pages blurry, which compress a PDF on a Mac without wrecking the scans explains, and the watermark options are basic. Test on a few copies before you trust a workflow with a client’s files.

The Shortcuts app has PDF actions too, such as Make PDF and Split PDF Into Pages, and a shortcut can be offered in Finder’s Quick Actions menu from its details. If you already build shortcuts, it is worth a look; for watermarks, passwords and Quartz filters, Automator’s actions are more direct.

Put the steps in a safe order

When a batch involves several steps, the order matters more than people expect. A sequence that avoids most problems:

  1. Fix the pages first. Rotate, reorder and delete pages before anything else, because later steps stamp every page. Fix a scanned PDF that is sideways and out of order covers this.
  2. Make scans searchable. Text recognition works best on clean, upright pages. See make a scanned PDF searchable on a Mac.
  3. Merge or split, if the batch needs to become fewer or more files.
  4. Stamp: page numbers, Bates numbers, watermarks, headers and footers.
  5. Compress, once the content is final.
  6. Add passwords last. Once a PDF needs a password to open, most tools cannot open it to make further changes, so encrypting earlier means removing the password again.

Name and keep the outputs straight

A batch job can produce a lot of files that look identical in a Finder window. Three habits keep it manageable:

  • Never overwrite the originals. Send output to its own folder, named with the date and the job, such as “2026-10 watermarked”.
  • Rename in one step. Select the finished files, Control-click, choose Rename and add text such as “-final” to every name at once. Rename a batch of files at once with Finder shows the options.
  • Check the first and last file properly. Open them, count the pages, search for a word if they should be searchable, and look at one page closely if you compressed. If those two are right, the middle almost always is.

When repeating PDF steps is part of the job: Basalt

If you run the same PDF steps every week, such as numbering, watermarking and compressing a set of documents, built-in tools start to feel thin. Basalt is a native Mac PDF app with eighteen tools in one window, including Merge, Split, page organizing (reorder, rotate, delete), Compress, Make Searchable, Passwords, Bates Numbers, and Watermark with headers and footers. Its Procedures tool saves a sequence of steps so you can repeat it, rather than rebuilding the job by hand each time.

Every Basalt tool writes a new file and never modifies the original, which removes the most common batch-job accident. Everything runs on the Mac; the engine that opens documents runs as a separate process with no network access, enforced by macOS. Basalt needs macOS 13 Ventura or later and is free for 24 hours with every tool, then $29 for a lifetime license on up to 3 Macs. It works on PDFs and images converted into PDFs, and it does not edit PDF text like a word processor.

Questions

Can Preview process a batch of PDFs? Preview can open several PDFs at once in one window, but edits and exports still happen one file at a time. That is fine for three files and tedious for thirty.

What happens if one PDF in the batch has a password? Most batch steps cannot open a PDF that needs a password, so that file will fail or be skipped. Remove the password first if the file is yours; remove the password from a PDF you own shows how.

Do Quick Actions or Automator upload my files anywhere? No. Both run on the Mac and work on the files in place or on the copies you tell them to make.