Quite often there are situations when, for example, to organize documents or make them easier to read, it is necessary to combine several PDF files into one. You can glue PDF documents in a few simple ways. But when performing some operations, you should take into account some nuances.
How to merge PDF files into one using Adobe Acrobat Professional?
The most traditional method of combining several files of this format into one document is to use the native Adobe Acrobat program, preferably the Professional version. If you try to perform such an operation in the usual "Reader", nothing will work.

You can merge PDF documents using the main file menu of the application, in which you need to select the Create PDF document item and go to the Combine Files into a Single PDF line. In the window that appears for selecting the necessary objects from the bottom in the format line, you need to set exactly PDF, since by default it is supposed to open all supported formats.
Now you need to select files. Note that if you select them while holding down the Shift key, the selection will also affect intermediate objects, so you should use a click with the Ctrl key, and then click the add button (Add). After that, the selected files will appear in the special File to Combine area. Here it is worth paying attention to the fact that the order of objects will directly depend on their position when selecting (sorting). To move the document up and down, you need to whiten it with a left click and use the Move Up (up) and Move Down (down) buttons. These buttons can be found in the dedicated Arrange Files area. In addition to them, there is also a button for deleting the selected document (Remove). To view the received order, use the normal preview button.
When everything is ready, it remains to press the "OK" button, after which you will be asked to save the received document. The file type field indicates the PDF format, and then it simply confirms saving.
How to merge 2 or more PDF files with format conversion?
If you don't have the above program, you can take a roundabout way. You can glue PDF documents using PDF to-j.webp

First, you need to convert PDF files to-j.webp
Using special utilities
The second option for a large number of documents is quite inconvenient. Therefore, to simplify the work, you can use a small free utility called PDF Split-Merge (which, by the way, allows you to merge and split files of this format).

In this case, you just need to add the files in the correct order and start the conversion process.

You can also glue PDF files using the Foxit Phantom PDF application. Fundamentally, the actions from the previous program are practically the same. Only the names of the main menus and commands differ. But this utility is interesting because when combining documents, you can set a limit on the size of the created file, and if you wish, you can still edit the text, and even replace fonts.
Online document processing
Finally, if the user is too lazy to deal with such transformations, on the Internet you can find many specialized resources like PDF Joiner, where documents can be combined online. Everything is simple here: you just need to add the files in the order in which they should be in the new document, if necessary, swap the documents, and then activate the start of processing. When the conversion is completed, you just need to download the result to your computer. The only limitation is that you can add no more than 20 objects at a time.