With the portable document format (PDF), you can create professional-looking documents that can then be viewed with a PDF reader or viewer. While you often need a paid application such as Acrobat Pro to create a PDF, you can easily find a free PDF viewer for almost any popular platform. PDF readers can be standalone desktop or mobile apps, or they can be built into a Web browser.
PDF readers offer a similar and small set of features. All of them enable you to view the text and graphical elements in a PDF file. Most PDF readers let you print the contents of a PDF, and a few free readers offer simple tools for annotating or marking up the PDF and applying a digital signature. With so many good free PDF readers available, one thing you should not need to do is pay for one.
You can find PDF readers as a dedicated app or as part of a related app.
Adobe Acrobat Reader
Google PDF Viewer
Google PDF Viewer lets you view, print, and search PDF files.
Preview, which is integrated in MacOS, lets you view and annotate PDFs, as well as sign and fill in forms.
Google Drive will automatically open any PDF stored in the cloud.
Viewing PDFs in E-book Readers