By Martin Jansen, Owner of Jansen-PCINFO
If you work in any business, sooner or later you will have to deal with PDFs or Portable Document Files. PDFs are the de facto method of sending unalterable documents between two parties. Adobe created the PDF format in 1993 and has increased the capabilities until 2011.
Now fully mature, PDFs can be opened by many readers, including Adobe’s own Acrobat Reader DC which is still free to download and install. Adobe, however, would like you to purchase their $15 per month Pro version. The free version can be hard to find, but I found it here: https://get.adobe.com/reader/otherversions/ Be careful and install only the version needed. Here is a screen print of the page with the Windows 64 bit version selected. You may not want the Chrome extension for PDF files, so uncheck that box if desired:
Acrobat DC is available for many Windows and MacOS versions. An Android version is also available.
Acrobat is not the only game in town, far from it. Windows and Mac users can install Foxit Reader here: https://www.foxit.com/downloads/#Foxit-Reader/ And here is an article about 9 other free readers: https://www.lifewire.com/free-pdf-readers-1356652
Long time readers know that I am a fan of open source software. PDF readers with the ability to annotate is hard to find and often is an expensive option. Fortunately, I found Okular for you. Okular can be installed from software repositories in the software manager in Linux and from the Microsoft Store. Sorry, Mac users, I could not test the installation from Mac Ports, but here is a link: https://ports.macports.org/port/okular/
The Windows and Linux version appear to be the same in function and usability. The PDFs when opened are quite clear with thumbnails of the pages on the left side:
The F6 key allows for many options for marking up the PDF. While the most common option is to mark with a yellow highlighter, adding text, watermarks and shapes are just as easy. What is the cost of this wonderful software? Nothing or, if you find value in Okular, a donation.
Tip: When saving the annotated PDF file, use another name to preserve the original PDF.
While PDF files are still being used around the world for unaltered communication, it has recently been challenged by HTML and XML as markup languages. Chromium based browsers have built in PDF readers and can even be used to fill out forms. Annotation capabilities, however, are difficult to find in free software. Okular is highly recommended.