How to force 2 documents to merge when you open them in Preview If the files have not merged in preview, you can merge them by printing them to PDF. In this description it will tell you whether there are one or two documents open. After this title there is a short description in brackets. If you open two documents in preview then have a look at the top of your preview window there is a title with the name of the document. Here’s how to tell if they have merged or not. If they are merged then all you need to do is save, but if they have not merged then you need to print them to a new PDF file. When you open 2 or more PDF documents in preview, depending on how you open them, preview will merge them together into one document OR it can open them as two separate documents. You can open them as seperate documents in Preview and drag pages from one to the other.

You can open them as seperate documents in Preview then merge them by printing them to one pdf file. You can merge them into 1 document in Preview as you are opening them. As with previous versions of OS X, there are 3 different ways that you can do this.

Apple have retained the ability to merge two PDF files with the built in ‘preview’ app in OSX El Capitan.

Document scanner for mac el capitan