The best free PDF reader 2021: powerful, feature-packed readers
The best free PDF reader can assist with editing, annotating and security with PDF files.
These days, PDF documents are being used everywhere. That's because they can be opened on any opening system, are easy to attach to an email or a website, and have the advantage of not being easily altered. And, so everybody uses them at work, in schools, and even for digital copies of the manuals for your peripherals and devices.
While simply opening a PDF as a read-only file is straightforward - you can just do it using your favorite web browser - editing, altering or converting one will require a dedicated PDF reader. Luckily, the best free PDF readers out there are just as capable as their paid counterparts, and they won't cost you a dime or force you into a monthly subscription.
To help you find the best one for what you need, we've highlighted five of the best free PDF readers for Windows and Mac. These should see you through advanced tasks like signing or editing documents, merging PDFs or converting between document formats. For more flexibility, take a look at our guide to the best free PDF editors, which make editing a PDF as straightforward as tweaking a Word document.
Adobe's free PDF reader isn't the most lightweight download, but this software does a lot of things well. If you already use other Adobe products, you can connect Acrobat Reader DC to Adobe's storage cloud. Alternatively, you can save PDFs to or open them from cloud services including Dropbox, Microsoft OneDrive, and Box.
What really sets this free PDF reader apart is that it can handle opening multiple large files at once. That means you can read through and annotate thick documents in this program without worrying that it will crash on you. The layout arranges individual documents in a tab view, so it feels a lot like the experience you'd get looking through PDFs in your web browser.
Acrobat Reader DC includes just about all the annotation tools you could want, making this hands down the best free PDF reader. It allows you to highlight text, add comments, and fill and sign forms. There's even a text-to-speech mode that will read documents out loud for you.
Foxit Reader is more than just a free PDF reader - you can also create PDFs from scratch using this software. Integration with Microsoft Office allows you to easily turn documents you're working on into PDFs. Or, you can scan a document or image and turn it into a PDF using Foxit Reader. The only thing that's lacking in the free version is support for optical character recognition in scanned documents.
The software can be a little intimidating at first, but it's relatively straightforward to navigate. That's thanks to the fact that it uses the same ribbon-style menu as Microsoft Office. Tools for editing, signing, highlighting, and commenting are fairly easy to access. You can also merge or split PDFs by downloading free add-ons for the software.
Note that with the software's latest update, Foxit seems to have removed its PDF virtual printer driver, meaning you can no longer use the software to create PDFs.
Slim PDF is the best free PDF reader for you, if you're looking for something incredibly lightweight. The software is just 1.43 MB in size, so it's the perfect choice if you're limited by hard drive space. Plus, that means that it's able to open and load your documents faster than most of its competitors.
The downside to this small size is that Slim PDF is pretty basic. You can search and rotate documents, but that's about it. There are no tools for signing, filling, commenting, or highlighting, let alone multiple reading modes. While there is a menu option to convert a PDF to a Word document, doing this requires another software download.
As a result, Slim PDF is truly just a PDF reader. It does a good job at this, though, leaving out the toolbars that can distract you from what you're reading. If you frequently need to print PDFs, Slim PDF is one of the fastest and most simple options available.
Nitro Reader is another powerful free PDF reader in the vein of Foxit Reader and Adobe Acrobat DC. What makes this tool different is that it has a touchscreen mode that's perfect if you're working on a tablet. Touchscreen mode is especially nice for reading e-books, since you can flick the pages rather than scroll or click on a button.
While you can't fill and sign PDFs with Nitro Reader, the software does a nice job of enabling collaboration. You can annotate documents with underlining and strikethroughs in addition to highlighting. Comments are also supported, and they appear like sticky notes that are easy to spot as you read through a document. Helpfully, the software also allows you to convert between PDF and other document formats.
The software has a ribbon-style menu that will be familiar to Microsoft Office users. The menu is pretty easy to navigate since there aren't all that many options available in Nitro Reader.
Expert PDF Reader is a lightweight software that doesn't skimp on tools. This software allows you to fill and sign documents, as well as includes a handful of pre-designed annotation markups like an “approved” stamp. You can also create sticky note-style comments or even attach additional documents to a PDF. The reader supports email documents, which makes the best free PDF reader for collaboration.
However, there are a few potentially important features missing. Expert PDF Reader doesn't allow you to convert between file types. Nor are there multiple reading modes to add to your security when opening downloaded PDFs.
The interface feels eerily similar to Microsoft Word, which will be a good thing for most users. The ribbon-style menu is fairly easy to navigate, and you can hide it when you simply want to read a document without distraction.