Sometimes the size of a PDF file is not ideal. Single-page PDFs may be too large or too small for your needs, while a multipage document may have some pages scaled in letter size, others in legal size ...
Use Preview: Open the PDF in Preview, click File > Export, select “Reduce File Size” under Quartz Filter, and save. Use ColorSync Utility: Open the PDF in ColorSync Utility, click File > Export, ...
PDF documents are fine—as long as you’re viewing them on large screens. But the thousands of people trying to view official documents or fill out PDF forms on mobile devices are stuck pinching and ...