Free PCI Compliance Scan: What It Actually Checks (And What It Misses)

If you've searched for a free PCI compliance scan, you've probably found tools like PCICompliance.com or PCIScan.org. They're legitimate tools. They check real things. But if your goal is understanding your PCI DSS 4.0.1 compliance posture — specifically the requirements that became mandatory on March 31, 2025 — they're checking the wrong layer.

This guide explains exactly what standard free PCI compliance scans check, what they miss, and why the browser layer of your checkout page is where your real exposure lives.

What Standard Free PCI Compliance Scans Check

Standard free PCI compliance scan tools were built around the infrastructure and network requirements that have been in PCI DSS since version 3.x. They are useful for catching baseline misconfigurations — but they were built before client-side browser-layer security became a mandatory requirement.

Here's what a typical free PCI compliance scan covers:

• SSL/TLS configuration — Is TLS 1.2 or 1.3 in use? Are deprecated protocols like TLS 1.0 and 1.1 disabled? Is the certificate valid, unexpired, and properly chained?
• Open ports — Are any unexpected ports open that could indicate unnecessary services or attack surface?
• HTTP security headers — Are headers like X-Frame-Options, X-Content-Type-Options, and Referrer-Policy present on public pages?
• Known CVEs — Are there publicly documented vulnerabilities associated with your server software or exposed services?
• HTTP to HTTPS redirect — Does your site enforce HTTPS across all pages?
• Cookie flags — Are cookies set with Secure and HttpOnly flags?
• Mixed content — Are any resources loading over HTTP on an HTTPS page?

These are real checks. They matter. A site failing any of them has genuine security and compliance issues worth fixing. But none of them touch the browser layer — and the browser layer is where PCI DSS 4.0.1 introduced its most significant new requirements.

What Standard Free PCI Compliance Scans Miss

Here's what standard infrastructure-focused free PCI compliance scans do not check — and what PCI DSS 4.0.1 now requires you to have under control:

• Third-party scripts executing on your checkout page — Every external JavaScript file loading on your payment pages. How many there are, where they come from, whether they have integrity controls. This is the core of Requirement 6.4.3.
• Subresource Integrity controls — Whether scripts are loading with cryptographic integrity hashes that guarantee the code delivered matches what was approved. Without SRI, any script can be silently replaced by an attacker.
• Content Security Policy on payment pages — Whether a CSP with a script-src directive is present on your checkout, cart, login, and payment pages. The absence of CSP is the single most common finding across all scanned e-commerce sites — and it's a direct Requirement 11.6.1 gap.
• Keystroke listeners attached to form fields — Whether third-party scripts have attached event listeners to input fields — the technical mechanism modern web skimmers use to intercept card data without touching your payment processor's code.
• Tag manager script injection — Whether Google Tag Manager, Tealium, or similar tools are dynamically loading additional scripts on payment pages. Each dynamically injected script is a potential supply-chain attack vector.
• Third-party data channels — Which external origins are receiving POST requests or beacon data from your pages. Any of these channels can carry form contents off-site depending on how the third-party script is configured.
• Inline event handlers on payment forms — onclick, onsubmit, oninput handlers directly in the HTML of payment-related elements — a documented formjacking attack vector under Requirement 6.4.3.
• Vendor exposure inventory — A complete map of every third-party vendor present across your payment pages — the foundation of the authorized script inventory Requirement 6.4.3 requires you to maintain.

Side-by-Side: Standard Scan vs. Client-Side Scan

Here's the direct comparison between what a standard free PCI compliance scan covers and what a client-side security scan covers:

Why the Browser Layer Is Where Your Real Exposure Lives

PCI DSS 4.0.1 introduced Requirements 6.4.3 and 11.6.1 because the payments industry recognized that the primary attack vector against e-commerce merchants had shifted from server-side breaches to client-side JavaScript injection.

Magecart attacks — the category of web skimming that has hit British Airways, Ticketmaster, Newegg, and thousands of smaller merchants — don't breach your server. They compromise a third-party JavaScript file that loads in your customers' browsers on your checkout page. The card data never leaves the browser — it gets intercepted before it's even submitted.

Your server can be perfectly secured. Your TLS can be flawless. Your SSL certificate can be valid. None of that stops a skimmer injected via a compromised third-party script tag on your checkout page.

That is why PCI DSS 4.0.1 Requirements 6.4.3 and 11.6.1 exist. And that is why a standard free PCI compliance scan — which checks your server and network — cannot tell you whether you're exposed to this attack vector.

Which Free PCI Compliance Scan Tool Is Right for You

The answer depends on what you're trying to assess:

If you need to satisfy a QSA's network scan requirement, use a standard ASV-certified scanner. If you need to understand your exposure under PCI DSS 4.0.1 Requirements 6.4.3 and 11.6.1 — the client-side requirements that became mandatory in March 2025 — a client-side security scan is the only tool that covers that ground.

Ideally you run both. They're checking different layers of the same compliance picture.

Free Scan vs. Deep Scan — Choosing the Right Level

The free CSI scan checks your publicly accessible pages — your homepage and any other pages a visitor can reach without logging in or going through checkout. It gives you an immediate browser-layer risk picture and tells you whether there are obvious gaps worth investigating further.

The $79 Deep Scan goes further — it covers your checkout, cart, login, account, and payment pages, produces a full evidence-based PDF report, and gives you the documented findings you need for a QSA review or internal remediation effort.

Start with the free scan. If it returns HIGH or CRITICAL, or if you need documented evidence of your payment page posture, the Deep Scan delivers that automatically to your inbox.