Purveyors of free antivirus programs serve a noble purpose, but they can't survive unless some users pony up for a paid version. Some sweeten the pot by adding significant security tools to their paid edition. Avira Antivirus Pro, by contrast, doesn't add much beyond what you get with the free product, and not all of the added features work well. The only real reason to pay for it is that the free edition is free only for noncommercial use.

At $44.95 per year, Avira is a little more expensive than the norm for standalone antivirus. The sweet spot seems to be just under $40. Bitdefender Antivirus Plus 2017, Kaspersky, and Norton hit this price point, as do more than a dozen others. F-Secure Anti-Virus 2016 and G Data give you three licenses for that price, while a three-license subscription to Avira costs $64.99. It's not a huge difference, but Avira's pricing is on the high side.

This app's main window is nearly identical to that of Avira's free antivirus. The Pro-only components are enabled, of course, and the window title says Pro. The button that urges you to Upgrade Now in the free edition changes to Renew. That's it for visible differences.

Shared With the Free Edition
Every bit of malware-fighting capability that comes in the free Avira Antivirus is also present in the Pro edition. Click the link and read my review of that product, or keep reading for a summary of my findings.

Lab Test Results Chart Malware Blocking Results Chart Antiphishing Results Chart

Avira's scores with the independent labs are quite good. Four of the five labs I follow include Avira, and its aggregate lab score of 9.3 points ties Bitdefender and beats almost all the competition. My calculation yielded 9.7 points for Norton and a perfect 10 out of 10 for Kaspersky Anti-Virus.

In my hands-on malware blocking test, Avira detected 97 percent of the samples, the same as Emsisoft Anti-Malware 11.0, Norton, and Trend Micro. Thorough blocking by Norton and Trend Micro Antivirus+ Security earned them each 9.7 of 10 possible points, but incomplete blocking of detected threats pulled Avira's score down to 8.9 points.

Webroot SecureAnywhere AntiVirus rules this test, with 100 percent detection and a perfect 10 points.

For a different view of protection, I challenge each product with 100 recent malware-hosting URLs, noting whether it keeps the browser from accessing the URL, eliminates the malware payload during download, or totally whiffs detection. Avira's Browser Safety component, which installs in Chrome and Firefox but not Internet Explorer, completely blocked access to 93 percent of the samples; another 2 percent were eliminated at the download stage. With 95 percent total detection, Avira beat out all others except Symantec Norton AntiVirus Basic, which exhibited 98 percent detection.

Avira Pro does include a Web Protection component that's not present in the free edition. I ran my malicious URL blocking test again, using Internet Explorer, so Browser Safety was not involved. The results were disappointing. Altogether, Avira blocked 91 percent of the malware downloads. Web Protection accounted for just half of those, with real-time antivirus wiping out the rest during the download. In most cases, the antivirus launched a mini-scan to make sure the download was entirely wiped out. These multiple mini-scans frequently caused Avira's use of CPU resources to spike at 95 percent or higher.

It's not clear to me why Avira doesn't use the same technology in Web Protection that serves so admirably in Browser Safety.

Browser Safety also serves to fend off phishing sites, fraudulent sites that attempt to steal your passwords. I tested the free and Pro editions of Avira side by side and found that the added help from Web Protection caught precisely one phishing site that Browser Safety didn't. The Pro version's detection rate lagged 27 percentage points behind Norton's, while the free edition came in 28 points behind. On the plus side, both products outperformed the phishing protection built into Chrome, Firefox, and Internet Explorer.

Both free and Pro editions come with a large entourage of associated Avira programs. Avira Connect serves as a launch pad for all the other Avira products, and it helps you connect to the online Avira portal. Phantom VPN protects your privacy on unsecure networks, for up to 1GB of traffic per month on a single device (for $9.99 per month you get unlimited traffic on unlimited devices). Avira Scout is a hardened browser with several security enhancements built in. Avira Software Updater checks for missing security updates, though its scope is seriously limited. And a trial version of Avira System Speedup lets you view the product's features and perform exactly one system optimization.

Other Pro Features
The Pro edition adds Mail Protection, which I thought might be a spam filter. It isn't. Rather, it scans incoming POP3 and IMAP email for malware. You can optionally set it to scan outgoing SMTP messages, though I can't picture how a malicious file could escape the real-time antivirus and then get caught by Mail Protection.

Most malware attacks come via the Internet, but there are a few malware families that spread via USB devices instead of, or in addition to, Web-based avenues. Some high-end security suites include device control, a business-centered feature that lets an administrator ban the use of unknown USB drives, but allow use of specific USBs. This feature works well in G Data Total Security and TrustPort Total Protection.

Avira's Pro-only Device Protection aims for similar control. When you insert a USB drive, it asks whether to allow or block access, with a checkbox to remember the device and whitelist or blacklist it. There's no obvious access to configuration for this feature. It appears nowhere on the main window, or in that window's menu. But if you click to configure PC Protection, you'll find a page for Device Protection that lets you turn the feature on and off and displays the whitelist and blacklist of known devices.

Of course, you need to prevent unauthorized users from just choosing to allow an unknown device. To that end, I enabled password protection for the product's configuration. However, password protection doesn't extend to the Allow/Block popup that appears for new, unknown USB devices. I had no trouble whitelisting an unknown, which defeats the purpose of this feature.

No Need to Pay
All of the best features in Avira Antivirus Pro also come in the free Avira Antivirus. Pro-only Web Protection does extend antiphishing and malicious URL blocking to all browsers, but it's less accurate than the Chrome-and-Firefox-only Browser Safety. And while Device Control aims to let an administrator prevent unauthorized users from mounting unknown USB drives, there's no way to lock it down so they can't.

If you like Avira and want to use it in a noncommercial setting, stick with the free edition. If you need antivirus for your business, pay a little less and choose one of our paid antivirus Editors' Choice products. Specifically, Bitdefender Antivirus Plus 2017, Kaspersky Anti-Virus, Symantec Norton AntiVirus Basic, and Webroot SecureAnywhere AntiVirus cost less, while McAfee AntiVirus Plus seems to cost more, but allows you unlimited licenses.