You can delete pages from a PDF on a Mac using the Preview app. You can also add pages to a PDF in two ways with Preview.

Learn how to add page numbers to PDF files using free online tools or PC software. You can set position, font, etc., for page numbering.

Pariah Burke walks you through the process of adding, removing, and replacing pages in complex Acrobat Pro PDF files.

You can add a variety of file types, including PDFs, text files, images, Word, Excel, and PowerPoint documents. The app converts all the files into PDF format before combining them.

Need to create a PDF or save your current document in that file type? We’ll walk you through how to convert Apple Pages to PDF on Mac, iPhone, and iPad.

Learn how to count pages in multiple PDF files together in Windows 11/10 using a web browser and free PDF page counter tools.

Gimp is normally used to create or manipulate images files, but can also work with PDFs if you understand how it works and what it's limits are.