UPDATED with most recent malware-detection test results. This review was originally published Oct. 10, 2019.
Norton Mobile Security for Android, listed in the Google Play Store as Norton Security and Antivirus, has consistently delivered, with both excellent malware protection and a slightly unique feature set that gives a bit of added value to its users.
While the premium version's yearly price was bumped back up since the last time I reviewed the app, it's no more expensive than some of the other best Android antivirus apps.
Norton's top selling point is the App Advisor, which screens apps in Google Play before you even download them. No other Android antivirus app we tested does this. However, Norton is still twice the price of Bitdefender Mobile Security, which delivers comparable malware protection and has some unique features of its own.
Norton Mobile Security costs and what's covered
Norton Mobile Security relies on the common freemium model, with a solid collection of free features and a yearly subscription to unlock full functionality.
The subscription fee for Norton Mobile Security is $29.99 (for a time, it was $24.99), but there is typically a deal on the first year for new subscribers that brings the initial yearly price closer to $15 to $20 in addition to a 30-day free trial.
As Norton is one of the largest computer antivirus companies, there are also options for those looking to protect their laptops and desktops along with their mobile devices.
The Norton 360 Deluxe package at $99.99 per year ($49.99 for the first year) supports five devices running Windows, macOS, iOS or, of course, Android. Norton 360 Premium bumps that up to 10 devices for, well, $99.99 per year.
You'll have to get Norton 360 Premium from a third-party retailer like Amazon or Fry's, but it's frequently discounted. You'll also get access to some of the best antivirus software and best Mac antivirus software available.
If you want identity protection as well, Norton 360 Deluxe can be purchased with three different levels of LifeLock service, but those bundles will run you up to $350 per year.
Like most Android antivirus apps, Norton Mobile Security no longer schedules malware scans. It instead offers a single toggle for "Smart Scan" that performs a scan "at the optimal time and frequency." You can choose whether you want it to scan system apps or your SD card, or do both.
A full scan took about 18 to 24 seconds to complete on my Google Pixel 3 when I opted to include everything, and about half that time if I didn't.
Norton's Web Protection alerts you to any malicious content when you are using the most well-known browsers, including the browsers built into Facebook, Pinterest and Snapchat, to name a few. When I navigated to a known malicious site, the Web Protection reliably prompted me with a warning on all six browsers that I had installed, but it did give me the option to proceed if I chose.
These web-protection features are part of the paid app, so while you enjoy the same malware protection with the free app, you'll miss out on this aspect.
Norton has scored perfectly on all of German independent lab AV-TEST's Android antivirus app evaluations for more than two years straight. No other brand has achieved this.
Bitdefender Mobile Security has come close, falling short only three times since January 2017 of detecting 100% of "real-time" malware encountered online. Like Norton, Bitdefender consistently detects 100% of the "widespread" malware collected by AV-TEST in the four weeks before a test.
Among the six other Android antivirus apps I reviewed in 2019, Avast Mobile Security, Kaspersky Mobile Antivirus and McAfee Mobile Security clustered behind Bitdefender with some perfect 100% detection scores, but more frequently scoring in the 99.7-99.9% ranges, especially with regard to real-time malware.
Google Play Protect, the built-in Android antivirus software that AV-TEST began evaluating in September 2018, performs terribly. Some of its detection rates are below 50%, while on average they are between 60% and 70%.
The remaining two Android antivirus apps I reviewed in 2019, Lookout Security & Antivirus and Qihoo 360 Security, no longer submit their apps for evaluation by AV-TEST.
Another lab, AV-Comparatives in Austria, included Norton in its most recent widespread overview of 250 Android antivirus apps in January of 2019, in which Norton managed a perfect 100%.
Avast, Bitdefender, Kaspersky and McAfee also all received a 100%. Lookout and 360 Security finished slightly behind at 99.6% and 99%, respectively, with Google Play Protect significantly back of the pack at 68.8%.
Norton was not part of a much smaller, more in-depth evaluation of 11 Android antivirus apps in July 2019. In those tests, Avast, Bitdefender, Kaspersky and McAfee all detected 99.9% of real-time malware, while Google Play Protect detected 83.2%.
Free security features and tools
Norton Mobile Security has a solid suite of anti-theft features, and it lets you remotely lock, locate, trigger a "scream," capture photos and wipe the device. These are all triggered from the Norton web portal at mobilesecurity.norton.com, which has a fairly bare-bones interface.
I tested everything other than a full device wipe. My commands were carried out within 1 or 2 seconds, but it could take between 5 and 7 seconds for the success message to display on the web portal.
In previous years, all these features could be triggered by SMS messages as well, but due to changes in Google Play store policy, this is no longer possible.
The SIM-card lock was a new feature the last time I reviewed the app and it remains available. The feature automatically locks your device if the SIM card is removed.
This feature is disabled at the moment due to changes in Google Play store policy. Norton is working with Google to find an acceptable solution, but there is no timeline for the feature's return.
Users of the free version who don't get the benefits of Norton's web protection can use the Safe Search feature powered by Ask.com. Searching here instead of in a regular web browser will immediately show either a green box with "OK" in it or a Norton logo to indicate that a site is safe to visit.
My primary issue with this feature is the ads. There are ad boxes at the top and bottom of each search-result page, with two text-based links in each one. That's four ads with only eight organic links per search page, so a third of your results are paid ads. Those ads don't go away for premium-version users.
Light-gray text in the upper-right corner of each box says "Ads," but I would prefer larger text or a different background color to more clearly set them apart.
Premium security features and tools
I'm still surprised that this useful feature hasn't been replicated by any of Norton's competitors, as App Advisor gives you a great deal of information on apps found inside and outside the Google Play Store.
The regular App Advisor section breaks down your installed apps into categories of potential concern such as "Unusual Behaviors," "Battery Usage" or "Data Usage." Tapping on an app gives you a detailed breakdown of that app, with scores of 1 to 5 in usage categories or specifics regarding where an app sends your data. Adobe Acrobat, for example, is flagged for being a significant battery drain.
App Advisor for Google Play offers similar data for apps as you browse the Play Store to help you make informed choices. Each time you browse to an app's page, Norton tells you what it knows about the app.
New and obscure apps may show up with "No Info," but the overall depth of the catalog is very impressive. Other Android antivirus apps have to wait until a new app is downloaded before they can scan and analyze it; with Norton, you'll get analysis before you even select the app for download.
Web links are a common vector for malicious content, and Link Guard protects you from them. It analyzes any link you tap on your smartphone and flashes either a green "Safe" or a red "Warning" banner across the bottom of the screen. If it's the latter, you will see a pop-up saying that Norton recommends not visiting the site, but it lets you choose whether you want to proceed.
Spam Call Detection
This feature is disabled at present due to changes in Google Play store policy.
This feature provides a quick overview of the security of your device based on a number of settings and potential vulnerabilities. The app will prompt you to fix any of these issues if they are detected.
This feature tells you if the Wi-Fi network to which you are connected has any specific security issues, such as no password protection. If you subscribe to Secure VPN with Norton, you'll get a button to turn on the VPN when you connect to an open network. (It's worth noting that Avast, McAfee and 360 Security offer this feature to users of free versions.)
This information is also available in App Advisor, but it flags apps that send your information to data centers and, when possible, identifies where those data centers are located. It's all interesting, but it would be nice if Norton offered some further explanations, as it does with battery and data usage.
To evaluate the impact of running Norton Mobile Security on my device, I conducted multiple tests using the Geekbench 4 Android benchmarking tool on my Google Pixel 3 phone running Android 9.0 Pie. I first established a baseline performance for the device before Norton was installed, then ran additional tests following installation and during a full malware scan.
Following installation of Norton Mobile Security, my phone's performance dipped 4.32% below its baseline average on Geekbench 4. Interestingly, a full scan had slightly less impact at 3.9% off the baseline.
The post-installation performance score on installation placed Norton in sixth among the eight apps that I tested, although there were only a couple of percentage points separating Norton from the fourth-place finisher. The full-scan results were very good, ranking at No. 2, behind only Android's built-in Google Play Protect.
Setup and support
Setting up Norton Mobile Security was quick and easy, with just a handful of permissions needed to get underway, along with signing up for a Norton account. It's pretty clear if a feature hasn't been set up yet, but you will likely miss something on your first time through the app.
Norton's tech support is second to none, with live chat and phone support open 24 hours a day, seven days a week. The online forums and knowledge base also do a good job with handling some of the more common questions.
Norton Mobile Security has seen virtually no changes to the user interface since I last reviewed the app in mid-2017, and that's not a complaint. The Material Design rebuild the app went through a few years ago still feels modern and intuitive.
While its pricing may make it a difficult sell, the consistency and reliability of Norton Mobile Security should nevertheless keep it on your shortlist. Every feature simply works (except those Google no longer allows), and Norton's malware detection has been unwaveringly perfect for years.
Bitdefender Mobile Security holds a similar regard from me among the best Android antivirus apps, and costs half the price of Norton after the first year. Each of these apps has a couple of unique pieces, so take a look at them to determine which is the better fit for you. But between the two, there's no wrong answer.