Two PDFs, one upload slot. It might be a signed page and the rest of the contract, a cover letter and a resume, or the front and back of a form scanned separately. Merging two PDFs into one is about the simplest PDF job there is, and you can do it for free on any device.
This page covers the quickest method that works everywhere, the built-in way on a Mac, how to put one PDF inside another rather than at the end, and what to check before you send the result.
The quick way on any device
The merge PDF tool on this site works in the browser on Windows, Mac, iPhone and Android. Nothing to install, no account, no watermark.
- Add both PDFs. Select Choose PDFs and pick the two files, or drop them onto the page. Each appears as a card with a thumbnail of its first page, its page count and its size.
- Check the order. The card on top becomes the first pages of the merged file. Drag the cards to swap them if needed.
- Merge. Optionally type a name for the new file, then select Merge PDFs. The combined file downloads straight away.
Your files never leave the device. They are opened in your browser's memory and combined there by pdf-lib, an open-source library, and if a file trips up pdf-lib, the tool switches to qpdf, a second open-source engine. Pages are copied as they are, not re-drawn: text stays selectable and images aren't re-compressed.
If either PDF has a password, its card asks for it. The password stays on your device. The merged file is saved without a password.
Which file goes first?
It sounds obvious, but this is where most do-overs come from. A few rules of thumb:
- Cover material first. A cover letter, a form's first page or a signed summary goes on top; supporting pages follow.
- Follow the request. If a landlord or office lists the documents in an order, use that order.
- Dates run oldest to newest for statements and pay stubs, unless you were asked otherwise.
When in doubt, open both files and look at their first pages before you merge. It takes ten seconds and saves sending the file twice.
On a Mac with Preview
Apple's Preview guide describes merging the whole contents of two or more PDFs:
- Open the first PDF in Preview and choose View → Thumbnails.
- Drag the second PDF's icon from the Finder onto that thumbnail sidebar, dropping it after the last page (or wherever it should go).
- Drag thumbnails to fix the order.
Apple warns that Preview saves changes automatically. To keep the first PDF as it was, choose File → Duplicate before you start and work on the copy.
On Windows
Windows doesn't include a PDF merger: its Microsoft Print to PDF printer makes one PDF from one print job. The browser tool above works in Edge or Chrome; combining PDFs on Windows covers it in detail, along with Adobe Acrobat's Combine files for anyone who has Acrobat.
On iPhone or Android
Open the merge PDF tool in Safari or Chrome. Pick both PDFs from Files, iCloud Drive, Google Drive or your downloads, drag the cards into order with a finger, and select Merge PDFs. On iPhone, save the result to Files or share it straight into Mail. For other quick fixes on a phone, see how to edit a PDF on iPhone.
Putting one PDF in the middle of another
Sometimes the second PDF doesn't belong at the end. A signed page 4 needs to replace an unsigned one; an appendix goes after chapter two. There are two ways:
| Goal | Steps |
|---|---|
| Insert a PDF between pages | Split the first PDF where the insert goes, then merge three files: part one, the insert, part two |
| Move a few pages after merging | Merge the two PDFs, then drag the pages into place with reorder PDF |
| Replace one page with a new one | Merge, move the new page into place with reorder PDF, then remove the old page with split PDF |
In Preview on a Mac you can do all of this in one window, since you drag individual page thumbnails.
What changes when you merge
- Page sizes stay as they were. A US Letter page and an A4 page can sit side by side in the same PDF.
- Quality stays the same. Nothing is re-drawn or re-compressed by the merge tool, so the merged file is about the size of the two together.
- Bookmarks, internal links and fillable form fields are not carried over by the browser tool. Text, fonts and images are. If one of the PDFs is a form you still need to fill in, fill it and save it first.
- Scans stay scans. A PDF that is a picture of paper stays unsearchable. To make it searchable, run it through image to searchable PDF.
Check before you send
- Count the pages: the merged file should have the two page counts added together.
- Look at the page where the files meet, to be sure the order is right.
- Rename the file to say what it is, not "merged.pdf".
- If it is too large for an email or upload form, shrink it with compress PDF.
Where this comes up
A rental application is a common one: the signed application, a pay stub and an ID often need to arrive as one file. The renting an apartment scenario lists the papers landlords usually ask for, and making a PDF on iPhone helps when one of the pieces is still a photo or a web page.