PDF Reader Download: Free Apps to Open, Read and Annotate PDFs

If all you do is open and read PDFs, a lightweight viewer like SumatraPDF starts almost instantly and barely touches your system resources. If you need to fill forms, sign documents, add comments or work with protected files, a heavier app such as Adobe Acrobat Reader or PDF-XChange gives you those extras. Decide what you actually need before installing.

For most home users, a middle-ground reader covers reading, basic annotation and printing without feeling bloated.

Several free readers let you highlight text, add notes and complete interactive forms. Adobe Acrobat Reader is the reference implementation and supports nearly every PDF feature. Foxit Reader is a lighter alternative with similar tools. On Mac, the built-in Preview app handles annotation and signatures without any download at all.

• Highlighting and notes for studying or reviewing.
• Form filling for applications and government documents.
• Signatures for approving contracts without printing.

If you prefer open source software, SumatraPDF is a fast, minimal reader for Windows that also opens ePub, MOBI and comic book formats. On Linux, viewers like Okular and Evince ship with most desktop environments and offer annotation as well. These projects are transparent about their code and free of bundled extras.

Mobile reading is where a good app really shines. Adobe Acrobat Reader has well-rated iOS and Android apps with reflow mode for small screens, and most platforms include a basic viewer in the files app. For e-book style PDFs, an app with night mode and adjustable text size makes long reading sessions far more comfortable.

PDF readers are a frequent target for fake download pages because they're so widely searched. Go to the vendor's official site, watch out for installers that try to add browser toolbars, and on the Adobe page in particular, untick the optional extra offers (such as antivirus trials) before downloading. A quick malware scan of any installer never hurts.