ZDNET’s most recently updated guide names Bitdefender Total Security the best antivirus software of 2026, and recommends Norton for anyone protecting only one device. The pick rests on hands-on trials of malware detection and system slowdown, weighed against feedback from security professionals and Trustpilot reviews. ESET Protect is ZDNET’s separate pick for business customers.
PCMag UK and TechRadar test independently and land on the same winner. Tom’s Guide does not. It names Norton 360 Deluxe the best antivirus overall, after weeks of installing, testing, and calling each brand’s support line.
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What the top pick gets you
Bitdefender Total Security runs on Windows, macOS, Android, and iOS, and ZDNET prices it at $30 a year, discounted from a higher list price. It blocks malware, rootkits, and ransomware, spots phishing attempts, stops unauthorised webcam and microphone access, and bundles a VPN for subscribers. ZDNET also credits the company with publishing its own research on cyber threats and building ransomware-decryption tools.
A limited free version of the software exists for anyone who wants to try it before paying. ZDNET’s Trustpilot score for Bitdefender sits at 4.2, and the site discloses that a purchase made through its links can earn it a commission.
Why the testers don’t all agree
AV-Test’s February 2026 report gave Bitdefender, Norton, and McAfee the identical top mark: 6 out of 6 across protection, performance, and usability. In its April 2026 test, AV-Comparatives scored the three differently on how much they slow a PC down. Norton measured 5.3 on that scale, McAfee did better at 3.3, and Bitdefender came last of the three at 9.6.
Tom’s Guide put that impact score to a real test. It ran a demanding video game while Norton 360 Deluxe completed a full scan of almost 900,000 files, and watched the frame rate drop from 118 to 105, a fall it calls barely noticeable. PCMag UK, meanwhile, puts Bitdefender’s own aggregate lab score at 9.6 out of 10 across four of the five testing labs it follows. Its hands-on malware test rated the software only “mediocre,” despite the software catching every phishing sample it tried.
Does Windows already cover you?
Microsoft’s own support pages hold a fact most “best antivirus” lists skip. Microsoft Defender Antivirus comes built into Windows 10 and Windows 11, and it turns itself back on automatically if no other real-time security product is installed, or if that product’s protection has lapsed.
The software offers two kinds of check. A quick scan looks in the places malware is most likely to hide, and suits a routine health check. A full scan searches everywhere, takes longer, and is what Microsoft recommends when a PC shows signs of infection.
Why a second program can make things worse
Microsoft is direct about running Defender alongside something else: don’t. It advises against operating more than one real-time antivirus or antispyware product at the same time. Running two together can slow a PC down and sometimes throw an error code such as 0x80070643. Anyone installing a new security product should first uninstall the old one.
That rule does not apply to on-demand tools such as the Microsoft Safety Scanner, which only run when asked or on a schedule, and so can sit alongside real-time protection without conflict.
What a paid subscription still buys
Which?, the UK consumer group, put 11 Windows antivirus products through repeated rounds of testing in January 2026 and found free antivirus now comparable to many paid packages on detection. Some free versions carry more pop-ups pushing an upgrade. The clearest difference in a paid tier is the number of devices it covers, plus extras such as a VPN, parental controls, and secure file backups. It also warns that a renewal price can jump sharply after the first year, in one case more than doubling from £40 to £96.
The Independent takes a starker view of what Windows leaves out. Its reviewer calls Windows 11’s built-in Defender “very surface-level,” and says the best paid software adds extras such as a password manager and identity monitoring. Even a well-reviewed extra can come with a catch. The VPN bundled into the Independent’s own pick, Bitdefender Total Security, is capped at 200MB of traffic a day, low enough that its reviewer expects most subscribers to leave it switched off.
Whichever program a reader ends up choosing, the volume of threats it has to hold back is not in question. The AV-TEST Institute counts more than 500,000 new malware samples registered every day. Before adding a new one to a PC that already runs Defender, the simplest check is Microsoft’s own: look at what is already switched on, and remove it first.
