
Thanks so much. Your explanation is brilliant. Easy to follow. Better than apple support itself. :)
OS X comes with a free application called ‘Preview’ that will open automatically whenever you click on a pdf file. Preview can edit and merge pdf files but the official Apple instructions are not quite right. Here’s how to do it depending on which version of OS X that you have.

You can merge PDF files using the built in ‘Preview’ application that comes for free with OSX, you don’t need 3rd party paid software.
The basic concept for merging 2 pdf files is the same for whatever version of OS X you have. You open the first file, view the page thumbnails, then drag the second file into the first file and save the new file. Exactly how this works varies depending on which version of OS X that you have. Apple have changed the details a few times. Sometimes there’s a green plus sign to indicate the merge. Sometimes there’s a grey border. If you don’t get it right the 2 files will not merge. You need to read the directions for the exact OS version that you have. (To find out which version of OS X you have just go to the Apple Menu and click ‘about this mac.’)
Please click on the version of OS X that you have to find out how to merge a pdf file:
How to merge PDF files in High Sierra (10.13) (2018)
How to merge PDF files in El Capitan (10.11) (2015)
How to merge PDF files in Yosemite (10.10) (2014)
How to merge PDF files in Mavericks 10.9 (2013)
How to merge PDF files in Mountain Lion 10.8 (2012)
For all versions of OS X prior to Mountain Lion (10.7 and earlier) just follow the instructions below.
Here’s how to join two or more pdf files together using Preview in OS X 10.7 and earlier:
1 Open the pdf file in preview.
2. Open the thumbnail view (Shift-⌘-D)
3. Drag a second pdf ON TOP OF an existing page thumbnail.
When you drag in step 3 it must drag to on top of the thumbnail, as in over it, not above it.
This is a bit hard to explain, the best way to grasp the concept is to look at the pictures below. Can you notice that the thumbnail on the right has an extra grey border compared to the thumbnail on the left. The grey border indicates that the files are merging.

RIGHT WAY: Drag the new pdf file overlapping an the existing page and they will merge into one – creating one pdf document out of the two. (Notice the extra grey border compared to the left photo.)
.
.
.
SUMMARY: To combine two separate PDF files into one document you need to drag the new pdf ON TOP OF an existing thumbnail until the grey border appears – then it will merge the two pdfs together. (You can then save the new merged pdf.)
If you drag it into the sidebar but not on top of an existing page the new file will be added as an external link – not merged into the original pdf document.
Published Date:Last Updated: Dec 2017.
Read on for how to do it step by step.
Thank you!!! So, so helpful!
worked like a charm – but on 10.6 osx i didn’t get the icon double border when laying the next pdf over the last page of the previous. just a blue bar where i wanted to put it.
did a print -save as PDF to combine several into one single PDF. opened it and none of the hyperlinks work. they still appear blue/underlined, but no longer retain the web addresses. I checked the individual pdfs and they have the links intact. What happened to them when I combined them and resaved as a single PDF? did i save it wrong?
ok, i just answered my own question. If I print and select save as PDF – it throws out the links. But if I do a save-as and rename the combined files, it creates the new Single PDF with links intact.
maybe my goof will help others who make the same mistake
Thanks for the detailed instructions. I couldn’t get the drag and drop method to work, but I used the print method successfully. Today I had a neighbor come over to my house frantic about how to merge over 2,000 small pdfs into a single document. We came across this post, and a few minutes later: bam! We were finished.
OK, so this does NOT work for me at all. I have tried it both ways and they will not merge. I am running 10.7.4. If anyone has another suggestion, I would welcome it!!
Thanks ver much for posting… way easier than the adobe equivalent method on adobe
Extremely helpful article! Thanks very much :D
This method worked really well in Snow Leopard, but having upgraded to mountain lion having similar problems to KIM. Tried the print route, but the dialogue box would not give me the save as pdf option, only post script.
I have 3 pdf docs of 1 page and trying to create one doc. Any ideas
thanks
It works in lion – just make sure you drag on top, and that the documents are not locked.
Thank you! Saved a lot of time…
Perfect! Thanks!!!
Felt like a dummy asking anyone ;) thanks buddy.
fantastic, thank you!!!
You can also use PDF Burger to merge PDF files online – http://pdfburger.com
It is a free service.
Thank you!!!!! so much more easier than reading all the above.
Thank you!!! You saved me so much money!
Thank you very much! It’s so simple and yet so hard to do it when you don’t have the knowledge. THX!!!
This is amazing and I definitely didn’t think of it! So simple! Great post!
Yes, I used to be able to do this in earlier versions of preview by “dragging on top,” as these instructions suggest.
But NO!!!!..these instructions NO LONGER WORK: I’m on a MacBook Pro, 10.8.4, running Preview, 6.0.1.
Is there another way?
Works in 10.8.3 – I’ll update my macbook to 10.8.4 and see what happens!
It does work, but only if ALL the files you are trying to combine are PDF files; it will not work with png, jpegs, etc.
Yes, this still works in 10.8.4 so you must be doing something wrong. Make sure the pdf file is not password protected.
If you don’t have any joy with Preview then there are plenty of apps on the app store for joining, splitting, extracting pages from PDFs for example: https://itunes.apple.com/us/app/pdf-basics/id711503268?mt=12
A nice alternative to the Preview app you find on Smallpdf’s Merge PDF. It’s a nice tool that feels similar to the preview app but it gives you a few more options for the format and it doesn’t require any download.
So easy!! I didn’t even need to read the step by step. :-) Thank you!!!
So easy!! I didn’t even need to read the step by step. :-) I’m on iMac 10.8.5 and it worked. Thank you!!!
It works, however the output results into insanely huge files. Converted 2 3MB JPG files to PDF using Preview and merged them: result 25 MB. Deal breaker.
Thank you soooo much!!!!
Thanks Mate
THANKS!
That is not true. That used to work on previous versions. I have upgraded to 10.8.5 and there is no longer any way to merge PDF files.
Mac is getting as primitive as PC.
Thanks, you put in crucial details that others left out.
Another thing – the one you start with (add to) has to be a pdf.
eg – I wanted to string a set of jpegs into a single pdf. I opened jpeg #1 in one window and the rest in a second window. I dragged #2 on to #1 but it would not add. I had to save #1 as a pdf and reload it. Then I could add the jpegs to that.
Yes good point. You can’t add pdf’s to a jpeg, but you can add jpegs to a pdf.
Thanks so much! As already mentioned: without the crucial details I would’ve spend another lost hour to get the PDFs merged. THANX !!! ;-)