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Avast Free Mac Security review

Avast Free Mac Security is the best free Mac antivirus program, but has so-so malware protection

Avast Free Mac Security
(Image: © Avast)

Our Verdict

It's the best free Mac antivirus program, but has so-so malware protection.


  • Free
  • Nearly no system impact in background
  • Phishing protection
  • Password manager included
  • Scans email attachments for threats


  • Malware protection isn't perfect
  • Bloatware still annoying

Avast Free Mac Security doesn't break a lot of new ground. As is the case with even the best free antivirus software, it does an OK job and — like popular free-to-play games — aims to pull money from your pockets after it's installed.

The one major perk of Avast Free Mac Security is that it can identify attacks in your email inbox, a feature that we'd like to see in all Mac antivirus services. 

At the end of the day, though, Avast's Mac malware protection rate isn't quite as good as its competitors', which is the most important part of the best antivirus software. Nonetheless, we think it's the top free option among the best Mac antivirus software.

Avast Free Mac Security costs and what's covered

Avast Free Mac Security is free. It supports Macs running any version of macOS, as long as they have 128MB of RAM and 750MB of available disk space.

Antivirus protection

Avast Free Mac Security keeps Macs free of malware using traditional signature-based detection by unpacking Mac-specific file formats and scanning them for malicious content. It also uses its artificial-intelligence system to apply lessons from its user base to train its software.

Avast also thwarts PC malware on Mac, to prevent it from spreading on networks, and scans unopened ZIP files. It performs system protection scanning in the background, permits both on-demand and scheduled scans, and can scan your router to protect you against DNS hijacking and other threats.

Antivirus detection

Avast Free Mac Security's on-demand malware-scanning engine has a mixed record in recent lab tests. It stopped 100% of malware in tests conducted by Austrian lab AV-Comparatives in July 2018 and June 2019.

(Image credit: Future)

Results from German lab AV-Test were less consistent: 100% of Mac malware was detected by Avast in June 2018 and June 2019, but Avast caught only 96.3% of malware in December 2018. (Both labs also test the best Windows antivirus software and the best Android antivirus apps.)

(Image credit: Future)

That means Avast tied with Bitdefender Antivirus for Mac and Kaspersky Internet Security for Mac on the AV-Comparatives test (both hit 100%). However, it failed to match Bitdefender, Kaspersky and Norton 360 Deluxe on the AV-Test study, in which all three earned 100% scores.

(Image credit: Future)

Of all the Mac antivirus programs we tested, Avast Free Mac Security was the only one that flagged items already on our system as threats. Specifically, it found three email messages in my old, inactive, Outlook database that contained links to phishing websites.

Security and privacy features

Avast Free Mac Security includes Avast's Online Security browser extension, which automatically installs itself in Chrome unless you opt out, while Firefox provides a confirmation prompt to make sure you approve the extension. The Avast extension appears as a button that is green when you're safe and red if a site is potentially harmful. Similar flags will appear next to search results.

(Image credit: Future)

If you're wary of sites that monitor your actions, the Avast browser extension also displays a counter badge that tallies the number of activity trackers found in a website and provides an additional option to block social network-based tracking.

(Image credit: Future)

Not only does Avast scan activity on your hard drive and web browsers, but it also monitors POP3 and IMAP email clients, including Apple Mail, Thunderbird, Postbox and Airmail, and scans email attachments as well as email messages.

(Image credit: Future)

Avast monitors your computer and its network connections in the background, scans new files upon installation and lets you schedule scans. However, Avast Free Mac Security doesn't have any of the extra features offered by paid competitors, such as parental controls, a VPN service, firewalls or webcam blockers.

Performance and system impact

Avast Free Mac Security had a moderate impact on system performance, which we assessed by running our custom Excel VLOOKUP benchmark test, which matches 60,000 names and addresses on a spreadsheet. Our test machine was a 2017 MacBook Air with a 1.8-GHz Intel Core i5 CPU and approximately 54GB of data stored on a 128GB SSD.

(Image credit: Future)

With Avast Free Mac Security installed on our MacBook, but without any active scans running, the VLOOKUP test finished in an average of 3 minutes and 38 seconds, 1 second longer than without any antivirus software installed. That's a passive system hit of less than 1%, and not something you would likely perceive.

MORE: Antivirus Software Buying Guide

Other antivirus products' passive system impacts ranged from 5% (Sophos Home Premium) to zero percent (Bitdefender). This is overall great news for Mac users: Most of the time, you'll never notice that you've got antivirus software running.

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You would be more likely to notice the slowdowns created by Avast's active scans. During full-system scans, the VLOOKUP test finished in an average of 4 minutes and 59 seconds, resulting in a big performance dip of 37 percent. That's not as bad as McAfee AntiVirus Plus' 47% fall (the worst offender), although it wasn't as good as Sophos' 7% full-scan system hit.

Avast's full-scan completion time, which took an hour and 11 minutes on average, was on the longer end of scores but was not the longest we found — Sophos' 2-hour-and-56-minute time was the longest. Malwarebytes for Mac Premium's full scan took a miraculous 16 seconds, while Bitdefender closed its full scan in 4:25. Kaspersky (41:20) and Norton (25:49) fell in the middle of the pack.


Avast Free Mac Security may not be the prettiest antivirus app, but it provides a number of functions and options. Its main window shows users a Protected status, as scans are enabled by default. All other features, including on-demand scans, are located in a menu bar on the left.

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Avast's main window presents users with their status — Protected or otherwise — and a "Run scan" button that pushes you to Avast Cleanup Pro. You'll be confused by this abrupt switch of apps if you weren't paying attention to the fine print, and you'll soon realize that Cleanup Pro is a paid product that looks to tidy up your hard drive and costs between $2.99 or $3.99 per month.

After you click that Run scan button once, it changes to an Upgrade button for Avast Security Pro, which features anti-ransomware protections and Wi-Fi and network scanning. To avoid further confusion, click on Scans in the left-hand menu, which opens that section as well as other sections of the app, such as Reports, Virus Chest, Shields and Preferences.

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In Scan, you can select from a number of different types, such as scans of custom directories, scans of removable volumes and scans of your home network. Avast also includes scheduled scans, an increasingly rare option these days.

Clicking on New Scan presents a Start button for activating a Quick Scan and a Change Scan Type button to switch to a full-computer scan.

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You'll find database updates and analyses of scans performed on your system in Avast's Reports. Avast places files it flags as malicious into the Virus Chest quarantine section, where you can delete or restore them (if you think Avast is mistaken).

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Open the Shields section to see real-time analysis of scanned files. Annoyingly, if the file directory is especially long, Avast won't give you the full directory, so you can't go look up the offending file for yourself. You may not need to, but we'd prefer to have the option.

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In the Preferences tab, you'll find options to change the frequency of notifications, system updates and scans. Here, you can also disable hard-drive, email and web protection, although Avast wisely makes you enter your system password first. Additionally, you can disable Avast's menu-bar icon from this window (it's under Miscellaneous).

(Image credit: Future)

If you create an account with Avast, you can check the status of any systems you've logged into in the Account tab as well as at Avast's menu-bar button provides links to open the main interface window, see current activity and application information, and review previous notifications.

Installation and support

To install Avast Free Mac Security, you open and click Download, which will place the installer DMG on your Mac. (Thankfully, you won't have to go through anymore, an annoying part of the previous model.) After you click through the end-user-license agreements, the installer will download more files and install Avast.

(Image credit: Future)

No restart is required, and the whole process took about 2 minutes for me, which felt about normal. In the middle of the installation, you get the option to not install Avast's unlimited Password Manager and the company's SecureLine VPN client. The Avast Online Security browser plug-in is free, but you get only a seven-day trial of SecureLine VPN service, which otherwise starts at $60 per year.

(Image credit: Future)

To get technical support, click Help in the menu bar, select Avast Technical Support and then select Contact Help to open Avast's Support site. Here, you can find a FAQ, ask for help in the forums and call a customer-support line that will provide free advice for installing, configuring, updating and removing Avast.

If you need more help than that, Avast offers paid support starting at $79 for any call that isn't related to removing a virus or malware, or at $119 per call for virus-related calls. For more support, you can spend $199 for a year of unlimited service, or $10 per month plus a $99 setup fee.

Bottom line

Avast's email scanning gives it an edge over competing Mac antivirus products. It needs such an advantage when the rest of its package is such a mixed bag.

Not only does Avast's software continually push you to spend money on additional services (unlikely if you've already chosen to use free antivirus software), but its malware detection rates aren't great overall.

If you're going to pay, you should instead choose Bitdefender Antivirus for Mac, which gives you excellent protection and a low system impact for $40 a year. If 

you'd rather not pay, then Avast is the best free option, but only because Sophos Home, which has a more full-featured free tier, has undetermined malware-protection abilities on Macs.