The best Internet security software typically includes three essential components -- antivirus, anti-spyware and a firewall -- along with optional features, such as a spam filter and parental controls. Some companies bundle additional components as well, including identity theft prevention, anti-phishing software and online backup. Smartphones are increasingly vulnerable to malware too, and we cover both PC and smartphone Internet security software in this report, as well as some double-duty products that protect both PCs and mobile devices.
In naming the best Internet security suites, we look first to performance, but also ease of use and features. Of course, the most important feature of any Internet security software is its antivirus protection (and if that's all you are interested in, we review stand-alone antivirus software programs in their own report).
Among all-in-one security suites, we see terrific feedback for Bitdefender Total Security 2015 (Est. $60 for 3 PCs). It scores well in testing and earns raves from professional reviewers including Editors' Choice selections at PCMag.com and Tom's Guide. User reviews are more mixed, but that's not an unusual situation with most Internet security software, especially commercial suites. Bitdefender earns top scores in most independent lab tests, including a 100 percent detection rate against both new and established malware by AV-Test.org.
Bit Defender offers comprehensive protection. "It pulls together almost every imaginable security feature in one package, and they all work well," says PCMag.com's Neil J. Rubenking. Those features include antivirus, anti-phishing, anti-spyware, a software firewall, parental controls, PC tune up and optimizer functions, file encryption, anti-theft, online backup and more. New this year is a feature that monitors usage to change your profile -- say for movie watching or game playing -- to keep spurious warnings and intrusions to a minimum. It's supposed to work automatically, but Sarah Jacobsson Purewal at PC World reports that the performance of that feature was inconsistent.
If everyone only used PCs, we might be done at this point, but they don't, and we aren't. Mobile devices are increasingly vulnerable to malware attacks, and are more vulnerable to other issues -- such as being stolen or lost -- than PCs or laptops. Bitdefender Mobile Security (Est. $15 per year per device) scores terrifically in lab testing, and packs a lots of mobile goodies into the package. Those include a Privacy Advisor that tracks how your apps use your personal information and anti-theft features that will locate your device, or lock it and wipe the data on it. It can also trigger alerts and alarms on your Android smartwatch if it and your smartphone are out of range of each other. You can also buy Bitdefender Mobile Security and Bitdefender Total Security 2015, along with Bitdefender Antivirus for Mac ($60 for 3 Macs), as Bitdefender Total Security Multi-Device for $100 per year for up to 5 devices, or $130 per year for up to 10.
If you have lots of computers to protect, or are looking for an-all-in-one security software solution for PCs, Macs and mobile devices, Norton Security with Backup (Est. $60 for 10 devices) is an excellent choice as well. Norton Security is Symantec's sole antivirus/Internet-security software product starting in 2015. It pulls the features and functions of the entire former Norton line, including Norton Antivirus, Norton 360, Norton Mobile Security, Norton Internet Security for Mac, and more into one package. Norton Security with Backup includes protection for any combination of 10 PCs, Macs or mobile devices (Android and iOS, including the iPhone and iPad). It also a utility to automatically back up files to either a cloud service (25 GB of online backup from Symantec is part of the deal) or an external drive. If you have a lot of devices to protect, that makes Norton Security with Backup one of the most economical commercial suites available. If you don't have as many devices to protect, and don't care about the backup feature, you can save a few dollars by opting for the base version of Norton Security (Est. $55 per year for up to 5 devices).
Whichever version you opt for, protection is first rate. Norton Security is an Editors' Choice at PCMag.com, and is also its pick as the best cross-platform multi-device security suite. AV-Test.org puts Norton Security at the top of the pile in its testing of both performance and usability. Norton products were once reviled as horrific resource hogs, but those days are now ancient history. The user interface has been greatly simplified over the years. One caveat is that testing of previous versions revealed good but not quite as bulletproof malware protection for Macs and mobile devices (the latest version is yet to be tested on those platforms). User feedback at sites like Amazon.com and Google Play is relatively strong. The biggest negative that reviewers find is that the most robust parental control features require the separate purchase of Norton Family Premier (Est. $50 per year).
What about free Internet security software? Try as we might, we could not find a totally free security suite for PC users that passes muster. Testing reveals protection that lags behind the best commercial Internet security software, and we see lots of reports of usability issues. However, if your main interest is in a solid antivirus product -- and that's what most concerns most users -- we did find some solid antivirus solutions that will do a terrific job of protecting your computer and not cost you one cent. For more on those, see our report on antivirus software.
That said, if you are only looking for the best free Internet security software to protect your mobile device, there are some suites worth considering. Chief among them is Avira Free Antivirus Security (Free). Testing by AV-Test.org and AV-Comparatives.org show that protection is solid. Feedback at Google Play is also strong. In addition to antivirus, Avira Free Antivirus Security can track your phone's location, and allows you to lock or wipe it if stolen. It can also block calls and contacts, and a new Identity Safeguard feature guards against hacked emails -- either yours or anyone on your contact list. Avira is available for both Android and iOS, and goes by different names in each platform's app store. For Android, it's called Avira Antivirus Security in Google Play. In iTunes, it's identified as Avira Mobile Security.
Avast! Free Mobile Security (called Avast! Mobile Security & Antivirus on Google Play) is another free Internet security suite for mobile devices. It also scores well in lab testing, is an Editors' Choice selection at Tom's Guide and receives solid user reviews at Google Play. However, Avast! Free Mobile Security is only available for Android devices.
Most independent test labs only evaluate antivirus software or the antivirus component of security suites. AV-Test.org is particularly helpful because it also rates factors such as usability and a suite's impact on a computer's performance. Technology websites generally defer to these labs when it comes to rating effectiveness, but PCMag.com conducts its own testing as well. Others, such as Tom's Guide and PC World focus their reviews on usability factors. User reviews at sites such as Google Play and Amazon.com are useful for evaluating how Internet security suites perform in the real world.