PDFs are tricky to edit without the right tools. While some of them are pricey, a few free ones can get the job done, too. Here's what you need to get—and know. Our team tests, rates, and reviews more ...

A watermark is a semi-transparent image that usually contains a logo or seal to identify who created a document or image. If you want to watermark a PDF file, you can either insert the watermark into ...