They can also create new PDF documents and forms from scratch. When you need to replace an image, change the text in a PDF, add new form fields, or edit anything else in a PDF, they're the apps you need. These tools-including Adobe Acrobat, Foxit, and more-often look like Office apps with detailed toolbars and menus, and can cost hundreds of dollars. The most professional PDF software is PDF editor apps. You can't change the core, original PDF text-but you can add to it much like you might write notes on a printed document. These let you add comments to PDFs, rearrange pages, add shapes and arrows to call out things in the document, and insert new text blocks and images into the PDF. Then there are PDF annotation apps, including macOS Preview, Xodo, and most mobile PDF apps. They're built to help you read PDF files like you would a book, and help you flip to the page you want, search through the book, highlight text, and perhaps fill out PDF forms and sign them digitally. The PDF apps you've likely used the most-Adobe Reader, Apple iBooks, Windows Reader-are PDF reader apps. → Want to make a PDF instead? Check our Guide to Making PDF documents to find out how to build your own PDF documents on any device.
