What is the best vulnerability scanner in 2026?

Nessus, from Tenable, is one of the best-known scanners among sysadmins. Professional runs on a machine inside your network, probes endpoints, servers, printers and network gear, and ranks what it finds by severity. User reviews keep praising the same two things: detection quality and a painless install.

Pricing is public, which is rare in this market: $4,790 for one year, $9,330.95 for two, $13,637.54 for three. Tenable's page mentions unlimited assessments and lists no IP cap, so for our 110 assets you still pay $4,790 a year. Add $400 for Advanced 24/7 support and $275 if you want the official training.

The complaints are consistent too. Users say the price has risen sharply over the last couple of years and find it very costly compared to OpenVAS. False positives create extra work, reports are awkward to hand to management, and the interface feels dated.

Watch out for Nessus Essentials, the free version. It covers 5 IPs on a 30-day license, and Tenable restricts it to strictly non-commercial use: no reports, no export, no compliance checks, no support, and plugins delayed by 30 days. Great for learning, not for protecting a company.

Tip: if you also need web app scanning, Tenable sells Nessus Expert at $6,790 a year. Price Detectify or Pentest-Tools first before you upgrade.

Intruder, a UK company, is a hosted scanner. Nothing to install: you add your domains, IPs and cloud accounts, and it runs scans on schedule. Under the hood it relies on two well-known engines, OpenVAS and Nuclei, and wraps the results in an interface built for non-specialists.

Its real edge is triage. Reviews are very positive, and one point keeps coming up: Intruder has its own security team review false positives you flag. That is exactly the top pain point with other scanners.

The Free plan is useful to get started: 5 web apps, 1 cloud account, 3 users, and a monthly network scan limited to ports 80 and 443. Cloud and Pro move to weekly scans, Enterprise to daily. Some users wish daily scanning wasn't reserved for the top tier.

Two limits before you sign. Internal network scanning only comes with Pro and Enterprise: on Cloud you only see what is exposed to the internet. And the pricing page shows no dollar amount for Cloud or Pro, just a base fee plus a small cost per target, before tax, with 20% off when billed annually.

Tip: the trial runs 14 days. Add every public IP you own on day one, even the ones you think are switched off. A forgotten server stays an open door for as long as it's online.

Vulnerability Manager Plus relies on agents installed on your endpoints and servers. It targets Windows fleets run by small IT teams, and it goes past the finding: it links each vulnerability to the patch that fixes it, inside the same console.

It is the cheapest paid option on this list for endpoints. Professional on-prem costs $695 a year for 100 endpoints. Servers sit on a separate grid on the pricing page, at $145 a year for 10 servers. The cloud edition starts at $895 for 100 endpoints, and Enterprise at $1,195. One technician is included; each extra one is $195 a year. A perpetual license is also available.

Keep in mind that an agent is one more piece of software to roll out and maintain on every machine. If your estate includes devices that can't take an agent, plan a network scan alongside.

Tip: before ordering, ask ManageEngine how the endpoint grid and the server grid combine for your exact estate. The page shows them separately, and that combined figure is the one to compare against Nessus.

Greenbone is the German company, based in Osnabrück, behind OpenVAS, the best-known open source scanner. It comes in two flavors. The Community Edition is free, with best-effort forum support. Paid offerings add a professional vulnerability feed, separate from the community feed, plus features the free version lacks, such as a master and sensor setup and offline updates.

The entry paid price is public: OPENVAS BASIC costs €2,524 a year (Greenbone lists euros only) for networks of fewer than 150 assets. Our 110-asset estate fits. Past 150, you move to OPENVAS SCAN, by quote.

Free has a hidden cost: your time. On sysadmin forums, people call OpenVAS far too complicated to set up and configure, and some conclude the Community Edition isn't worth the install effort. One detailed write-up on a home lab of about 20 machines found the container install easier but unstable, the source install reliable, and scans taking around 30 minutes per target.

False positives show up here too. The built-in answer is overrides, which let you reclassify or hide a finding you've verified. Some users also question whether the community feed catches as much as the paid one.

Tip: if you're new to it, start from a ready-made virtual machine rather than a manual install, and schedule a nightly feed update.

Detectify, from Sweden, looks at your business the way an attacker does from the internet: domains, subdomains, web apps and APIs. It is built for the web rather than for the laptops and printers in your office, which makes it the most relevant tool here if your revenue depends on a site or an app.

Pricing is public and quoted in euros only. The model: an annual platform fee, with assets (domains, IP ranges) billed on top. Starter is €0, with 5 users and API scanning. Standard starts at €2,500 a year and adds SSO. Professional starts at €5,000 and adds internal scanning in your CI/CD pipeline for one environment. Enterprise begins at €15,000.

Two useful details. If you take card payments, PCI ASV scanning adds €500 a year. Nonprofits get 30% off.

The catch: the entry price is never the final price, since every asset adds to the platform fee. List your domains and IP ranges before asking for a quote.

Tip: start on Starter to scan your APIs and judge the reports for free. You'll price your assets later already knowing the tool.

Pentest-Tools.com is a hosted platform that bundles network scanning, web app scanning and exploitation tools. Pick your targets, launch, read the report. No install, and plans split by use case, which makes it easy to size.

Prices are public and monthly. NetScan starts at $96 a month for 16 assets. AppScan, for web apps, starts at $140 a month for 5 assets. Exploit starts at $190 a month. Pay annually and you pay 10 months out of 12, so NetScan comes to $960 a year.

The limit shows up with our test estate. Sixteen assets don't cover 110 endpoints and servers, and the page doesn't list the price of the tier that would. It shines on a small scope: a few internet-facing servers, a website, a client engagement.

The Free plan gives 5 assets per cycle, without authenticated scans or API access. Enough to judge the reports before paying.

Tip: spend your 16 NetScan assets on internet-facing machines, and leave the internal network to a scanner you host. You pay the minimum for the riskiest part.

Qualys is one of the heavyweights of the market, with a fully cloud-based platform. Its full offering, VMDR, is sold by quote and aimed mainly at large organizations.

For a small business, the way in is the Community Edition. It is free, cloud-based, and covers asset discovery, infrastructure scanning and web app scanning. The real value: seeing what an enterprise platform looks like on your own network, with no commitment.

Be careful on two points. The official page doesn't state how many assets are covered or whether commercial use is allowed. Don't build compliance on it before you've asked Qualys directly.

The paid side's limit is the lack of any public price. To know what VMDR would cost for 110 assets you need a quote, which slows down any comparison with Nessus or Greenbone.

Tip: use the Community Edition as a second opinion. Run it on a few machines your main scanner already covers and compare. The gaps show you what either one misses.

Cyberwatch is a French vendor based in Paris. Its Vulnerability Manager maps your estate, scans it, ranks vulnerabilities by technical and business risk, and handles patching in a dedicated module. Business-risk ranking is simple in practice: a medium flaw on your billing server comes before a critical one on a test laptop.

Its strength is deployment. It installs on your own servers, with or without agents, and runs in disconnected mode. That is rare, and valuable for a plant floor, an isolated network or a team that wants no vulnerability data leaving the building.

The limit: no public price, everything goes through a quote. For a 110-asset business, that means a sales conversation before you even know if it fits the budget.

A word of caution: vendors in this space often showcase labels or certifications. Check any certification you're shown against the official issuer's site before it goes into a procurement decision.

Tip: send your inventory with the quote request (endpoints, servers, sites, air-gapped or not). You'll get numbers faster and can compare line by line with Nessus or Greenbone.