Here is a little secret: It is very easy to duplicate a page in Adobe Acrobat and most Acrobat users don’t know about this trick.
Open up Acrobat and display the Page Thumbnails pane:
Before we talk about how to duplicate a page, we need to spend some time to understand what we are seeing in the Page Thumbnails pane. On a very high level, all pages in the currently open PDF file are reflected as thumbnails. When you look at the active page, there are a number of different things we can do with the thumbnail view:
If not the entire page is displayed in Acrobat (e.g. we are viewing a page with a zoom level of 400%), the portion that is being shown is indicated in the thumbnail view. In the above screen shot, we can clearly see that the top of the page is brighter than the bottom of the page. The other thing we see is that the cursor is a little hand… This usually means that we can grab something and move it around. When we click on that bright portion of the page and move the cursor, we can pan around on the page. This makes it very easy to e.g. switch to a high zoom level, and by moving this box to the area of the page we are interested in. No more fiddling with the scroll bars to locate that small detail on a page.
Once we move the cursor away from that highlighted portion of the thumbnail and on to the lower part, the cursor icon changes to an arrow:
When we now click, something different is happening: The thumbnail gets selected (indicated by the blue border around the thumbnail in the screenshot). When we click on a thumbnail that is not the active page, the cursor remains an arrow, and the page gets selected. This means that if we want to select a page that is not currently shown, it does not matter where we click, but for the active page, this is important.
If we want to select the current page, we need to make sure that we click on a portion of the page that is not currently being shown (or, we can simply change which page is active in Acrobat in order to being able to select a page).
With the arrow cursor active, we can click on a page and we drag that page. This moves the selected page to a different location in the current PDF file – or it copies the page into a different PDF file if we drag it into a different “Page Thumbnails” pane. I can for example move the first page to the end of the document. The place where the page will be inserted is indicated by a blue bar:
So here comes the trick: When we hold down the Control key (or the Option/Alt key on a Mac) before and while we drag the page, that page gets duplicated: We are no longer just moving the page, we are inserting a copy of the page. Where that page gets inserted is again indicated by a blue bar:
There you have it, a simple way to duplicate a page in Acrobat.