Open-source might not be the first thing you think of with Windows, but these free tools can seriously boost your productivity.

Learn how to count pages in multiple PDF files together in Windows 11/10 using a web browser and free PDF page counter tools.

If you have a confidential PDF you want to password protect, you have a few ways to do that on your Windows 11 PC. You can use a desktop app or a web-based tool to encrypt your PDF files.

I am not sure why but people treat PDF differently than image files so I don't think there are very many that work for quickly viewing PDF *and* image files but you can certainly use something ...