Our Testing Methodology
Every antivirus on ShieldLabs is scored using the same repeatable process, so rankings reflect real differences between products, not marketing claims.
What we measure
Protection rate — Real and simulated malware samples, including recent zero-day packages, are run against each protected test machine in an isolated environment, tracking both detection rate and false positives on legitimate software.
Performance impact — We benchmark boot time, file-copy speed, and application-launch latency before and after installing each product, on identical hardware, to isolate the product's actual system footprint.
Pricing & value — List price, renewal price, device limits, and what's actually included (VPN data caps, password manager, identity monitoring) are compared against the protection and performance scores.
Platform coverage & UX — We install and use each product across the platforms it supports, evaluating setup friction, dashboard clarity, and support responsiveness.
How the overall /10 score is calculated
The overall score weights protection rate most heavily, followed by performance impact, with pricing and UX adjustments applied on top. A product with perfect detection but heavy system impact won't automatically outrank a lighter, slightly-less-perfect competitor.
Review update policy
Reviews are re-verified at least twice a year, or sooner if a vendor ships a major product change, a significant vulnerability is disclosed, or new independent lab data becomes available. The "last updated" date on each review reflects the most recent verification pass.
Why We Weight Protection Rate First
A fast, cheap product that misses real threats has failed at the one job it exists to do. We deliberately structure the formula so that no amount of polish elsewhere — a slick dashboard, an aggressive discount, a generous device count — can compensate for a weak detection record. This is a deliberate design choice, not an accident of the math: protection is the floor every other criterion sits on top of.
How We Handle Zero-Day and Simulated Threats Specifically
Known malware is the easy case for any modern antivirus engine. The harder, more revealing test is how a product handles something it hasn't seen before — a zero-day sample or a simulated novel threat built to mimic real-world attack behavior. We run these separately from known-sample detection and report them as a distinct data point in every full review, since a product that aces known-threat tests but stumbles on novel ones is telling you something important about its underlying detection technology, not just its signature database.
What Our Performance Benchmarks Actually Isolate
Performance testing is one of the easiest places for a review to go soft — running one quick scan and calling it "lightweight" tells you almost nothing. We run both quick and full scans, measure boot time and application launch latency before and after installation on identical hardware, and specifically watch for the gap between a product's idle footprint and its footprint during an active scan, since that gap is often where a "fast" antivirus quietly stops being fast.
Pricing & Value: What We Actually Compare
List price alone is close to meaningless in this category, since almost every product runs aggressive first-year discounts that don't reflect what you'll actually pay at renewal. We compare list price against renewal price specifically, check real device-count limits against what a typical household or small business needs, and price out bundled extras like VPN data caps or identity monitoring separately, since a bundled feature that's capped into uselessness shouldn't count the same as a genuinely unlimited one.
Qualitative Factors That Shape the Written Verdict
Some things resist a clean number but still show up in the review text: how aggressively a product pushes upsells during and after installation, how straightforward cancelling a subscription actually is, and how a support team responds to a real technical question rather than a scripted macro. These don't move the numeric score directly, but a pattern of manipulative upselling or unresponsive support gets called out explicitly, since it affects the real experience of owning the product.
The Honest Limits of This Methodology
No lab test can perfectly predict how a product will handle the exact threat that eventually targets your specific machine — the threat landscape shifts constantly, and even a top-scoring product can occasionally miss something genuinely new. Treat our scores as the strongest publicly verifiable signal available at the time of testing, and read the full written review for any product you're seriously considering, since that's where the specific test results and performance nuance get explained in detail rather than compressed into a single number.