Merge multiple PDFs into one — without paying for Acrobat

“Please send that as a single PDF.” And you have three: the contract, a scanned attachment, and a confirmation. At this point plenty of people either send three attachments with an apology, or go hunting for someone nearby who owns paid Acrobat. But merging PDFs is a free, routine task — built right into the system on a Mac, and available on Windows through free tools that run directly on your own computer.

How to do it

On a Mac (built in):

1. Open the first PDF in Preview and turn on the thumbnail sidebar (View → Thumbnails).
2. Drag the second PDF file from Finder straight into the sidebar, at the spot where its pages should go. Dragging thumbnails around lets you reorder or delete pages freely.
3. Save via File → Export as PDF (or just save) — done, the result is one continuous document.

On Windows:

1. Install the free PDF24 Creator (the maker offers all its tools for free) — it works offline, so your documents never leave your computer.
2. Open the Merge PDF tool, drag your files in, arrange the order, and click Merge. It can also reorder or remove individual pages.
3. Web services like iLovePDF or Smallpdf are an alternative — fine for a flyer or an invitation, but upload contracts, statements, or anything sensitive only to tools that run locally, never to someone else's server.

A practical detail: you can usually throw images into the merge too — PDF24 and Preview both insert a photographed document or a scanned page saved as JPG among the other pages as a full-fledged sheet of the resulting PDF. So you don't need to convert every photo to a PDF separately first.

A typical scenario

A parent is registering a child for a school trip: the application form, a doctor's note photographed on a phone, and a payment confirmation. The organizer wants one file. Instead of forwarding three attachments (and the inevitable follow-up “is that everything?”), they merge them into one PDF in two minutes, in the order the organizer wants to read them — application first, documents behind it.

What you get out of it

One tidy file instead of a pile of attachments — nothing gets lost on the recipient's end, and you come across as organized. And because these are free tools, the most common excuse for putting off merging disappears: the belief that it requires expensive software. Once you've done it once, you'll stop sending emails with four attachments and a note saying “hopefully that's everything.”

Pro tip

Scanned attachments come out best when made straight from your phone with OCR — and if you need to go the other way and pull something out of the merged PDF afterward, that works too, by printing the selected pages to a new PDF.