Best Free Antivirus 2019: 6 excellent ways to stay safe online

If you’re looking for an easy and inexpensive way to stay safe online, here is out round up of the best free anti-virus deals on offer. Or, if you’re not, you should.

The Internet can be a hazardous place at the best of times. With criminals trying to steal your personal data via emails and social media messaging, or launch cyber attacks using automated tools that don’t require any special coding knowledge.

The attacks also use nefarious tactics, like watering holes, which mean something as simple as visiting the wrong website at the wrong time can be dicey.

Watering hole attacks are a horrid attack by hackers that sees them hijack, or setup up bespoke sites, infected with dodgy code that attempt to infect any unlucky visitor that lands on them. If that wasn’t enough to concern you, there’s also the constant worry about companies monitoring your web habits to push tailored adverts to you.

But with so many companies pushing free anti-virus and data protection services, many of which have been shown to be complete snake oil. Knowing which to use can be tricky at the best of times. Here to help make sure you don’t pick the wrong free anti-virus solution we’ve group tested a selection of the most popular services to find the best currently available.

If privacy is your primary concern we’d recommend also checking out our best VPN guide, which details the best snoop blockers currently available.

Related: Best VPN

Best Free Antivirus 2018 – Which antivirus should I use?

Pretty much every one of the free anti-virus services we tested performed pretty well and will meet most users basic needs.

But Kaspersky Free Antivirus 19 and Microsoft’s integrated Windows Defender stand out as the best options for effective, hassle-free protection.

Kaspersky’s detection engine is unparalleled, although there’s still a paucity of dedicated test results for the free version. Windows Defender’s performance in multiple lab tests has surpassed anything we’ve seen before.

Both have low minimal impact on system performance, with Kaspersky being particularly well suited to computers with limited processor power.

Related: Best Laptop

Best Free Antivirus - Kaspersky Free AV 2018

RECOMMENDED: Kaspersky Free Antivirus 19


  • Outstanding malware detection
  • Free pop-up silent detection mode
  • Low impact on system load


Lack of dedicated test results for free version

Key features:

  • Email scanning module
  • Bootable rescue disk available as separate download
  • Windows Vista/7/8/8.1/10
  • Requires Intel Atom 1.6GHz or faster, 1GB of RAM, 920MB of free disk space, 64MB Intel GMA950 video card or better, screen resolution of at least 1024 × 600.

Score: 10

Kaspersky Free Antivirus uses the same detection engine as the company’s well-regarded commercial products, which puts it among some of the best-performing anti-malware tools around.

On installation, you’re asked to agree or opt out of recommended settings that will delete malicious tools, adware, auto-dialers and suspicious packages, and detect other software that can be used by criminals to harm your computer or data.

You’re also prompted to create an account, but you can back out of this; it isn’t required to use the software. Kaspersky Free installs with a 366-day licence that auto-renews when it runs out.

The desktop client closely resembles its paid-for counterpart in its clean look and feel, with a main screen that displays your protection status and options to scan your system, update its virus database and open extra tools. A number of other options are greyed out, prompting you to buy one of Kaspersky’s paid-for anti-malware suites if you click on them.

Kaspersky Free comes with a browser plugin to check for malicious links in your search results. We were pleased to find that this doesn’t change your default homepage or search engine, although by necessity it requires permission to read all your browser data.

You also get a copy of Kaspersky’s Secure Connection VPN service, with a 200MB daily allowance and an on-screen keyboard to foil keylogging malware.

File, web, instant messaging and mail scanners are included, but extra features such as ad-blocking and webcam protection are available only in paid versions. Advanced options allow you to set how paranoid the scanner is, schedule scans and configure the program’s default behaviour and the notifications you receive.

Disappointingly, this free version of Kaspersky’s software doesn’t make a regular appearance in most anti-malware testing labs’ results. As a result, we’ve had to rely on performance figures for Kaspersky’s other products using the same engine.

While their performance should be the same in both real-world and reference tests, the slight uncertainty resulting from this extrapolated methodology remains our only caveat on what appears to be a perfect choice for free virus protection.

Kaspersky’s engine protected against 100% of malware in SELabs’ real-world tests, including both web-download viruses and targeted attacks, with no false positives.

Similarly, it detected 100% of reference samples and real-world malware exposures across two successive months of trials by AV-Test. Performance data from the same source show that it has less of impact on system performance than most rivals, particularly when it comes to installing and launching software. However, it was rather heavy on website load times, particularly on a Core i3 system.

In AV-Comparatives’ real-world malware exposure tests, it defended against 99% of malware with no false positives.

Verdict: 10/10

We reckon this is the best free antivirus package you can download, boasting an excellent performance and plenty of features. Best Free Antivirus - Windows Defender AntiVirus 2018

RECOMMENDED – Microsoft Windows Defender


  • Excellent Windows 10 interface
  • Good malware detection
  • No need to install third-party software


  • System impact isn’t as low as you might expect

Key features:

  • Bootable Windows Defender Offline rescue disk available as separate download
  • Built into Windows 8/8.1/10
  • Available for Windows Vista/7 as Microsoft Security Essentials
  • Will run on any Windows system

Score: 10

Microsoft’s Windows Defender – the default virus protection built into Windows 7 and above – has gone from strength to strength in recent years, and its performance in the last batch of test results from multiple independent firms has been conspicuously good.

Its impact on system performance is low in general, particularly when it comes to launching websites and software on lower-powered PCs. However, using it in favour of third-party software may not provide the kind of performance boost that you might hope for.

That’s per AV-Test figures, which found that Avira, Kaspersky and Bitdefender all had less impact on overall system performance than Windows Defender.

Defender’s appearance and features vary depending on which version of the operating system you’re running it on. Windows 10’s Windows Defender Security Centre opens on a homescreen with an overview of your protection status, including when Defender last updated itself and scanned for malware.

It also has dedicated tabs for different features. Virus and threat protection is home to your usual quick, full and custom scans, plus an intensive offline scan mode to tackle hard-to-remove threats. You can manually update virus definitions and enable or disable options such as cloud-based protection and real-time protection – this isn’t a good idea.

The device performance and health section monitors anything that might go wrong with your system over time, also providing a “Fresh start” option that reinstalls Windows while retaining your files and most settings.

The firewall has its own tab where you can open ports, configure notifications and establish different settings for private and public networks. App and browser control allows you to set the strictness of Microsoft’s SmartScreen utility, which can warn against or block apps that Microsoft’s remote verification service hasn’t seen before.

You can even disable notifications from Defender via the Virus & Threat Protection settings, effectively giving it a much-needed silent detection mode.

Parental controls can be found under Family options. These provide device and account management for children who use Windows devices, allowing you to enable content filtering for the web, control the apps they install, alongside the amount of time they spend in front of the screen.

A recently added feature is ransomware protection and file recovery, which relies on Microsoft OneDrive as a secure backup target, although you only get 5GB of free space by default.

Although Windows Defender put in a dubious performance the last time we reviewed it, its latest results from three separate testing labs have been excellent.

In SELabs’ challenging real-world exposure tests, it protected the system in 75 out of 75 web-download malware exposures, and in all 25 targeted attempts to remotely compromise the system. This makes it one of just three anti-malware tools to get a full protection score.

It did just as well at AV-Test, where it protected against all reference samples and real-world malware exposure tests over a two-month period. AV-Comparatives’ real-world tests confirmed the trend, giving Windows Defender an accuracy rate of 100%.

Verdict: 10/10

Microsoft’s integrated anti-malware suite is currently so effective that, unless you need specific features or a slight performance boost, there’s little point in installing third-party anti-virus software.

Best Free Antivirus - Avast Free AV 2018

Avast Free Antivirus


  • Effective detection of drive-by download malware
  • Free pop-up silent detection mode
  • Clear, modern interface


  • Weak performance in targeted attack tests
  • Higher impact on system load than some rivals

Key features:

  • Email scanning module
  • Can create bootable rescue disk
  • Windows XP SP2/Vista/7 SP1/8/8.1/10
  • Requires Intel Pentium 4/AMD Athlon 64 or better, 256MB of RAM, 2GB free disk space

Score: 6

Avast’s free anti-malware suite is comprehensive and, in general, performs well – but it’s increasingly important to always opt to view custom settings during installation and setup.

Specifically, you’ll want to opt out of the Avast SafePrice price comparison browser extension, and prevent the Avast Secure Browser from taking over as your PC’s default web browser and launching automatically at login – unless you really want that to happen.

The default installation options also include a rather more helpful Online Security plugin for other browsers, which scans websites for malware and blocks ad trackers. There’s a built-in password manager, too, although we recommend using a dedicated tool for that.

Avast is refreshingly upfront about its data-collection policy: antivirus software typically collects information on its users’ habits and malware exposure as a matter of course – and clearly tells you how to opt out.

The software has a clean interface that follows Windows 10’s Modern UI style, with a main screen that shows your protection status and a one-button smart scan feature. Other features are available in the client’s Protection, Privacy and Performance tabs.

As you’d expect, you can run a variety of full and partial virus scans; view previously detected viruses; enable and disable Avast’s automatic file, web and mail scanning; scan your network for potential vulnerabilities; and create a rescue disk in case malware prevents your system from booting correctly at any point.

Avast has both a Do Not Disturb feature that will prevent it from showing pop-ups when specified programs are running in full-screen mode, and its usual Silent mode – available in the Settings menu – that prevents it from ever showing any pop-ups.

The program has a free, automatically renewing licence, and you can optionally connect it to an Avast account. The client shows unobtrusive adverts and extra feature buttons that promote the company’s paid-for products, which include a firewall, data shredder and system cleanup utility.

Avast’s advanced settings let you add URLs that you’d rather it never scan, have it scan for annoying-but-not-malicious unwanted programs to its scans, disable sound alerts and enable the program’s extra-paranoid Hardened mode.

Everyone tests Avast’s free antivirus product, which means that there are plenty of highly relevant test lab results to refer to. It detected 99.2% and 100% of AV-Test’s zero-day malware threats over a two-month period, and 99.9% and 100% of reference samples, with just two false-positive detections of legitimate software. It also did well in AV-Comparatives’ real-world tests, defending against 99.5% of malware delivered online.

Avast achieved a total accuracy score of 91% in SELabs’ real-world exposure tests – but that comes with a caveat: although it only let two standard web-delivered malware threats past, it proved to be particularly weak against targeted attacks, in which a malicious actor attempted to actively take over the system.

This means it isn’t quite as secure as some of its free rivals, such as Kaspersky, Avira and Microsoft’s integrated Windows Defender. AV-Test also found that Avast had slightly more of an impact than most rivals on the speed of launching, installing and copying files on a typical Intel Core i3 PC with 8GB of RAM.

Verdict: 6/10

Avast Free Antivirus is an effective malware deterrent with plenty of useful features, but its unimpressive performance against targeted attacks and its adverse effect on system load times mean that it’s difficult to recommend this AV software ahead of its competitors. 

Best Free Antivirus - AVG Free AV 2018

AVG AntiVirus Free


  • Free pop-up silent detection mode
  • Effective detection of drive-by download malware


  • Weak performance in targeted attack tests
  • Higher impact on system load than some rivals

Key features:

  • Email scanning module
  • Bootable rescue disk available as separate download
  • Windows XP SP3/Vista/7/8/8.1/10
  • Requires Intel Pentium 1.5GHz or faster, 512MB of RAM/1GB of RAM (Windows Vista and above), 1.2GB of free disk space

Score: 6

Since 2016, AVG has been owned by Avast, and both use the same virus databases and detection engines. This is reflected in their similar performance in testing, although there are minor differences to their default behaviour, particularly when requesting user interaction, which can make a critical difference.

Currently, AVG performs slightly better than its stablemate but lacks a couple of convenience features, such an integrated rescue disk creator. The AVG rescue disk, to be used in case malware renders your PC unbootable, is a separate download.

Like Avast, it’s a good idea to customise your options at install time, specifically to remove the SafePrice browser extension, which is a money-making price comparison tool that will pop up every time you try to shop for anything. If you’re happy with your current browser security then you may also want to opt out of installing the AVG Secure Browser; if you do install it, be aware that its Express Settings will set it as your default browser and have it open automatically when you log in to your PC.

AVG AntiVirus’s grey and green main interface provides a quick overview of your protection status, the time of your last scan and update, a quick-scan button, plus a relatively unobtrusive advert for AVG’s paid-for Internet Security software and some inactive buttons that highlight features you’ll get if you shell out for it.

AVG Free gives you critical real-time protection, and scheduled and on-demand scanning. However, the client also shows you which paid features you’re missing such as a firewall, encryption and anti-phishing tools. You can also optionally associate AVG with an online account and add extra paid-for features including a VPN and password manager if you want them.

Extra settings and options are available via a menu at the top-right of the client, including a file shredder to delete items so that they’re unrecoverable and access to your quarantined files.

You can enable a free pop-up silent mode if you’d rather not be bothered when your antivirus detects anything, disable email signatures marking email sent from a desktop email client as scanned and individually customise the sensitivity and behaviour of AVG’s email, web, software and real-time scanning components. You can also individually uninstall each of these components, but we wouldn’t recommend it.

We’ve included test results for AVG’s other products that use the same engine in our assessment of its performance results from major anti-malware test labs. During its most recent two-month test period, AV-Test found that AVG products protected against 99.2% of real-world zero-day malware attacks via web and email and 99.2% of a large set of reference samples in the first month, and 100% of threats in both categories during the next.

AV-Comparatives reports similar results, with AVG Free detecting 99.5% of real-world malware samples.

SELabs’ results are more nuanced, since they include both web-based threats and targeted attacks. While AVG Free stopped 73 out of 75 web-download malware threats, it only stopped 20 of 25 direct attempts to take over the system.

Its false-positive scores were excellent all-round, with only a handful of false detections of legitimate software in AV-Test’s suite, but AV-Test found that its impact on processes such as installing, copying and running software was a little heavier than many of its rivals.

Verdict: 6/10

Like the Avast Free Antivirus, AVG’s AntiVirus Free anti virus software is great for stopping malware, but crumbles in the face of targeted attacks

Best Free Antivirus - Avira Free AV 2018

Avira Free Antivirus 2019


  • Good malware detection performance
  • Low false-positive rate
  • Low impact on system load


  • No silent detection mode

Key features:

  • Can create bootable rescue disk
  • Windows 7/8/8.1/10
  • Requires 1GHz Intel Pentium 4 or better, 1GB of RAM, 2GB of free disk space

Score: 8

Avira Free Antivirus 2019 is relatively easy on system resources. Rather than cramming as many features as possible into a single utility, it presents a number of optional extras that you can choose to add at install time or after installing. These include a network scanner, a free 500MB per month VPN and system optimisation tools.

Avira’s interface is clean and surprisingly compact. It opens on a tab that displays your protection status, which modules are active, plus a couple of adverts for Avira’s other products.

Since this is the free version of Avira, some modules are marked as Pro only. So, you get its core real-time protection module, but not Antivirus Pro’s dedicated Web Protection and Mail Protection tools. Its firewall settings plug directly into Windows’ integrated firewall, but are pleasingly easy to use.

You can run a variety of full, custom and predefined scans on active processes, local and removable media, but everything is kept simple by design, so there aren’t a lot of other options cluttering the place up.

Quarantine and Activity tabs show you what the program has been up to, while Avira’s advanced settings allow you to tweak the behaviour and sensitivity of the scanner, add processes and files you’d like to exclude, and disable audio alerts.

Avira Antivirus Free uses the same detection engine as its paid-for siblings, which we’ve referred to for test data in some cases.

SELabs, as usual, tested Avira’s free product in its last home anti-malware report. It was one of the best performers in the lab’s targeted attack tests, in which the lab’s penetration test attempted to gain control of the computer. Avira resisted all 25 targeted attacks, as well as 72 out of 75 web-based, drive-by download malware infections.

AV-Comparatives’ most recent tests only featured the paid-for Avira Antivirus Pro 15, giving it a real-world exposure accuracy of 99.50%. This matches the performance we reported from a previously AV-Comparatives test, which included the Avira Free.

AV-Test only tests Avira Antivirus Pro, which uses the same detection and had both real-world and reference malware detection rates of 100% and 99.9 in successive months, with a single false positive. AV-Test also found that Avira’s impact on system load was among the best in the test, awarding it 6 out of 6.

Verdict: 8/10

By making all the its features optional, Avira Free Antivirus 2019 has a very low impact on system load speeds. That said, you’ll have to subscribe to the Pro edition to unlock some of its more useful features. Importantly, it also offers a solid performance for malware detection.

Best Free Antivirus - Bitdefender Free AV 2018

Bitdefender Antivirus Free Edition


  • Good malware detection performance
  • Low false-positive rate
  • Low impact on system load


  • Lack of dedicated test results for free version
  • Requires Bitdefender account

Key features:

  • Windows 7/8/8.1/10
  • Requires 2GHz Intel Core 2 Duo or better, 1.5GB of RAM, 800MB of free disk space

Score: 9

Bitdefender’s free antivirus suite isn’t as feature-packed as its paid-for siblings, but it uses the same detection engine. Unfortunately, like Kaspersky Free, it isn’t widely tested as a dedicated free product, which means we’ve had to rely on test results for other Bitdefender products that use the same malware detection engine.

Although Bitdefender has an excellent reputation and, where tested, its products generally do well – even its commercial versions feature in anti-malware tests a little less frequently than we’d like.

After installation – a process that includes a threat scan of your system – you’re prompted to sign into or create a free Bitdefender account to use the software. In a change from our last test of the software, we weren’t able to open the antivirus interface until we’d done so.

Bitdefender’s main interface is deliberately and refreshingly simple. A window shows whether your protection is up to date or not, and a button starts a system scan. Unusually, there’s also a box you can drag files and folders into for instant checking, which is very reassuring if you suddenly spot an unexpected or unknown file on your system.

A settings menu provides access to a log of events including scans, updates and detections; quarantined files; websites, files and directories that you wish to exclude from scanning which is useful for software developers who don’t want their unfamiliar new files to be flagged as potential threats.

There are also options to disable Bitdefender Protection Shield real-time threat monitoring, which we don’t recommend – and, under Account info, to turn off pop-up adverts for Bitdefender’s paid-for products, which we do.

Via your Bitdefender account, you get some basic online monitoring of your computer’s protection status and recent threads that the software has defended you against. Bitdefender runs in silent mode by default, so it won’t interrupt you while gaming or watching films, and it doesn’t include any extra plugins or modules.

It provides a good degree of malware protection, although its recent results from different testing firms have been surprisingly varied. Due to a lack of dedicated tests of the free version, we’ve had to rely on results from other Bitdefender products that use the same detection engine.

The Bitdefender engine was, once again, one of the few anti-malware tools to defend against all threats in AV-Comparatives’ current batch of real-world tests, and was the only one to get a 100% rating due to its lack of false positives. Similarly, it picked up 100% of both real-world and reference malware samples at AV-Test, with no false positives.

It had a generally low impact on system load, but slowed website loading on both Core i3 and Core i7-based PCs. Unfortunately, no Bitdefender products were included in the latest tests by SELabs.

Verdict: 9/10

This is an excellent option for anyone who’s after a simple and effective free protection tool.

Best Free Antivirus 2018 buying guide – What should I look for?

The key element of any antivirus software is its detection engine, which uses a combination of known signatures of malicious software and heuristic analysis of a program or file’s traits and behaviour to establish whether or not it’s potentially dangerous.

Detection engines are at the core of most antivirus companies’ business, and you’ll generally find that a firm’s free products use the same engines as the paid-for versions. Paid products justify their cost with extra features such as firewalls and system optimisation tools.

Modern antivirus software constantly monitors your PC and scans software, files and websites in real-time to detect potential threats, but you can usually still run manual and scheduled scans for extra peace of mind. Most AV programs run an optimised scan by default that checks the files most likely to have been compromised.

Best Free Antivirus 2018 testing and performance – How do you test AV software?

We’ve used test data on a per-engine basis, rather than an identical product basis. So, for example, we’ve used results from Kaspersky Internet Security to help draw conclusions about the Kaspersky Free, which uses the same engine.

The test data we’ve used was collected between August and November 2018, using the most up-to-date versions of the antivirus software available. AV-Test carries out real-world tests, in which systems are exposed to contaminated websites and emails, and reference set tests, in which several thousand malicious files collected in the previous four weeks are introduced to the system.

SELabs only carries out real-world testing, using live malware in the wild and targeted attacks designed to exploit known vulnerabilities in commonly installed software. These include both web-based exploits designed to compromise vulnerabilities in browsers, extensions and widely used software such as Java, and file format exploits against software such as Microsoft Word and Adobe Acrobat Reader, of the sort commonly found in malicious emails.

The company also carries out targeted attacks, in which the testing team attempts to actively penetrate, run commands on and copy data from a computer protected by antivirus software.

AV-Comparatives carries out a wide range of tests, updated monthly. In this review, we’ve used the firm’s real-world test results, which involve live exposure to malicious websites.

In all cases, we’ve directly quoted the percentage or number of malware exposures successfully defended against in tests, as well as performance metrics and false-positive test results, in which any blocking of benign software is noted.

It’s worth noting that there can be fairly dramatic performance differences from month to month, depending on a given antivirus package’s ability to detect the malware that’s prevalent at any given point, and the speed with which its signature database and heuristic detection rules are updated to reflect current malware.

AV-Test’s performance tests time the impact of different antivirus suites on a number of common desktop tasks, such as downloading and installing applications, launching programs, copying files and visiting popular websites. We refer to these performance metrics alongside the results of a processor benchmark carried out on our own test systems.

The price of free – How does free antivirus software make money?

While you don’t have to hand over any cash to use free antivirus software, its makers have to fund their business somehow. This manifests in a number of ways. Some products, such as Avira, show unobtrusive adverts, while others are paid to bundle software and services from other vendors with their product’s installer or web browser plugins.

Any product that’s available in paid-for, as well as free, versions will encourage to upgrade with varying degrees of persistence, with some including buttons for features that are only active for paid users in their main interface. Many free AV providers encourage users to register for free accounts by providing online monitoring tools that you can use to manage and secure other devices associated with the same account, such as phones and tablets.

Our reviews detail any obtrusive advertising or promotional features in each free AV suite and, where possible, tell you how to avoid them.

In addition, antivirus software by default reports back to its manufacturer when it encounters unknown malicious and even benign files. This data gathering is an important function of free antivirus suites as far as their creators are concerned. In practice, it means that the malware databases the software relies upon are kept constantly up to date, helping to protect all its users, whilst making both paid-for and free versions more accurate.

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