Website security scanners help you find vulnerabilities before hackers exploit them. But not all scanners check the same things, and most free tools have significant limitations. We tested seven of the most popular free website security scanners to see what each one actually detects.
We ran each scanner against the same set of test sites (including a known compromised WordPress site with active cloaking) and evaluated them on: detection accuracy, scan depth, speed, usability, and what they check beyond basic security.
Best for: Comprehensive auditing (security + SEO + hack detection in one scan)
URL: leadauditpro.com/audit
LeadAuditPro's full website audit covers 8 categories in one scan: SEO, Performance, Security, Technical, Accessibility, Content, Trust, and Privacy. The security checks include HTTPS verification, security header analysis (CSP, HSTS, X-Frame-Options, etc.), mixed content detection, and cookie security.
What sets it apart is the integrated hack detection — it runs a separate async scan that fetches pages as both Chrome and Googlebot to detect cloaking attacks. This caught the Indonesian gambling spam on our test site that every other scanner missed. It also includes trust signal analysis (fake review detection, trust badge verification) and privacy checks (exposed PII, API keys) that no other free scanner offers.
Limitations: Advanced features require a free account. The hack scan takes 15-30 seconds for multi-page checks.
Best for: Quick malware and blocklist scanning
URL: sitecheck.sucuri.net
Sucuri is a well-known name in website security. Their free SiteCheck tool scans for known malware signatures, checks blocklists (Google Safe Browsing, Norton, McAfee, etc.), and verifies your SSL certificate. It's fast and gives a clear pass/fail result.
Limitations: Only scans one page. Doesn't detect cloaking (it fetches with its own User-Agent, not Googlebot's). Missed the Indonesian gambling spam on our test site because the spam only activates for Googlebot. No security header analysis.
Best for: Security header and configuration analysis
URL: webscan.upguard.com
UpGuard focuses on server configuration and security headers. It checks for HTTPS, security headers, email security (SPF, DKIM, DMARC), and known vulnerabilities. The report is well-structured and gives a letter grade.
Limitations: No malware or hack detection. Doesn't scan page content at all — only server headers and configuration. Won't catch injected spam, cloaking, or compromised content.
Best for: Technical vulnerability scanning
URL: pentest-tools.com
More technical than the others. Pentest-Tools scans for known web server vulnerabilities, outdated software versions, open ports, and common misconfigurations. It's closer to what a penetration tester would run.
Limitations: Free version is limited to 2 scans per day with basic checks. No content analysis, no hack detection, no SEO checks. Requires more technical knowledge to interpret results.
Best for: Continuous monitoring (free tier)
URL: hostedscan.com
HostedScan runs OpenVAS vulnerability scans and offers a free tier with limited monthly scans. It's useful for ongoing monitoring of server-level vulnerabilities. The dashboard is clean and enterprise-grade.
Limitations: Free tier is very limited (3 targets, basic scans). No website content analysis. Focused on infrastructure, not web application security. Slow scans (can take 30+ minutes).
Best for: SSL/TLS certificate analysis
URL: ssllabs.com/ssltest
The gold standard for SSL certificate testing. Gives you a detailed grade on your HTTPS implementation, including protocol support, cipher suites, certificate chain, and known vulnerabilities (Heartbleed, POODLE, etc.).
Limitations: Only tests SSL — nothing else. No malware scanning, no security headers, no content analysis. Essential but narrow.
Best for: Checking if Google has flagged your site
URL: transparencyreport.google.com/safe-browsing
Google's own tool tells you if your site is currently flagged as dangerous. If it is, your site will show warnings in Chrome and in Google search results. This is the official source — if Google says you're flagged, you're flagged.
Limitations: Only tells you if you're ALREADY flagged — doesn't detect new hacks that Google hasn't found yet. By the time you're flagged here, the damage is already done. No preventive scanning.
| Scanner | Malware | Cloaking | Headers | SSL | SEO | Trust | Free Tier |
|---|---|---|---|---|---|---|---|
| LeadAuditPro | Yes | Yes | Yes | Yes | Yes | Yes | Unlimited |
| Sucuri SiteCheck | Yes | No | No | Yes | No | No | Unlimited |
| UpGuard | No | No | Yes | Yes | No | No | Limited |
| Pentest-Tools | Partial | No | Yes | Yes | No | No | 2/day |
| HostedScan | Partial | No | Yes | Yes | No | No | 3 targets |
| SSL Labs | No | No | No | Best | No | No | Unlimited |
| Google Safe Browsing | Flagged only | No | No | No | No | No | Unlimited |
No single scanner catches everything. For the most thorough free assessment, run LeadAuditPro's full website audit (covers SEO + security + hack detection + trust + privacy in one scan) and supplement with SSL Labs for deep SSL analysis if needed.
If you only have time for one scan, choose a tool that checks what Google sees — not just what you see. Cloaking attacks are the most common modern hack vector, and only tools that compare browser vs. bot rendering can detect them.