You don’t even need to sign in to use the free PDF reader. If you only need to view a PDF file, you can upload it from the homepage, give it a second or three to process, and you’re in. PdfFiller is an online PDF editor built for creating and altering documents in your browser, with desktop apps for Windows, Mac, Android, and iOS. It's less effective than Acrobat DC, with ads, but it should serve you well. If you strictly need a free PDF reader for Windows, there's also Adobe Acrobat Reader DC (opens in new tab). This service costs around $20 / £20 / AU$30. Meanwhile, Acrobat Pro DC gives you access to all the listed features – plus it’s also compatible with Mac devices.

However, it only works on Windows devices. The subscription costs around $13 / £13 / AU$20 per month when paid for annually. Acrobat Standard DC which lets you create, edit and sign PDF documents. If you’re interested in purchasing Acrobat, there are two offerings to pick from. And if you’re writing a letter or have been sent an important form, you can add your signature by using the Acrobat app on a touchscreen-enabled device. You can even use the built-in preview feature to see what the document will look like on different screen sizes and resolutions. What’s more, when you create a PDF document using Acrobat, you’re sent a smart file that you can edit, sign, share and search. That could be handy if you’re looking to compare different drafts of the same piece of work. There’s also a new file comparison tool, which quickly and accurately analyzes two PDF files to find any differences. With the software, you can use your smartphone camera to capture and turn any document into a high-quality PDF. Adobe Acrobat Document Cloud provides you with the tools to download, convert and edit PDF files across computers, tablets and smartphones. Software giant Adobe not only pioneered the PDF, but it has also created a highly popular and comprehensive application that lets you manage such documents effectively.

There are more advanced products out there

Open source pdf viewer for windows 7