Client-side security monitoring, compared
There are four ways teams try to catch tampered and unauthorized JavaScript on their pages. Here is an honest look at what each one can — and cannot — do, and where ScriptPatrol fits.
Header-only security graders
Score your HTTP response headers and TLS configuration and hand you a letter grade. Useful and fast — but by design they read only what your server returns. They never see the JavaScript that actually executes in the browser, so a tampered script earns the same grade as a clean one.
Embedded JavaScript-tag monitors
Inject a tag or agent into your pages to watch scripts at runtime. They do see the browser layer — but you are adding another script to the very pages you are trying to protect, with a performance cost, and a tag can itself be blocked, broken, or tampered with.
Server-side / WAF
Firewalls and server-side controls protect your infrastructure and filter requests. They are essential — but they sit in front of the browser, not inside it, so they cannot see a skimmer that runs entirely client-side after the page loads.
ScriptPatrol
Loads your real pages from the outside the way a visitor’s browser does — no tag, no agent, no page-load weight. It fingerprints every script, detects changes against a verified baseline, grades each page A+ to F, maps where the page sends data, and reads the real page even behind Cloudflare.
Capability by capability
Compared by monitoring approach, not by specific product. Each column reflects what that approach can inherently do; ScriptPatrol’s column reflects shipped features.
| Capability | ScriptPatrol | Header-only graders | Embedded JS-tag monitors | Server-side / WAF |
|---|---|---|---|---|
| Sees live, in-browser script integrity | Yes | No | Yes | No |
| No tag or code to install on your site | Yes | Yes | No | Yes |
| No added page-load weight | Yes | Yes | No | Yes |
| Continuous change detection vs a baseline | Yes | No | Yes | No |
| A+ to F Security Score (headers + TLS + script integrity) | Yes | Partial | No | No |
| Data-flow map — where the page sends data | Yes | No | Partial | No |
| Reads the real page from outside, behind Cloudflare | Yes | Partial | Yes | |
| Known-vulnerable library + malicious-host checks | Yes | Partial | Partial | No |
| Approval trail + PCI DSS 6.4.3 / 11.6.1 evidence | Yes | No | Partial | No |
Where ScriptPatrol fits
Header graders, a CSP, and a WAF are all worth having — and ScriptPatrol is built to sit beside them, not replace them. Its job is the one blind spot they share: the live JavaScript running in your visitors’ browsers, on the pages where a skimmer does the most damage. Because it installs nothing on your site, you can add that layer without touching your stack.
Common questions
- Is ScriptPatrol an alternative to a header-only security grader?
- It covers what they do and adds the layer they cannot. A header grader scores your response headers and TLS; ScriptPatrol scores those too, then adds live script integrity — whether the JavaScript on the page still matches a verified baseline — into a single A+ to F Security Score. A header-only grade cannot tell you a script was swapped; ScriptPatrol can.
- How is ScriptPatrol different from an embedded JavaScript-tag monitor?
- A tag monitor adds a script to your pages to watch from the inside. ScriptPatrol watches from the outside — no tag, no agent, and zero added page-load weight — so there is nothing extra on your checkout to slow it down, break, or be tampered with. For onboarded customers an optional WAF allowlist gives a clean, complete read; either way there is never code to embed.
- Do I still need a Content-Security-Policy or a WAF?
- Yes — they are complementary, not replaced. A WAF protects your infrastructure and a CSP restricts which scripts may run. ScriptPatrol is the monitoring layer that tells you what is actually running and when it changes. If you run a CSP with a report-uri, you can even point it at ScriptPatrol to capture runtime violations in between scans.
- Can I use ScriptPatrol alongside the tools I already have?
- Yes. ScriptPatrol is designed to sit beside your existing graders, WAF, and CSP and fill the client-side blind spot none of them cover. Because it installs nothing on your site, adding it changes nothing about your stack.
- Which approach is right for me?
- If you only need a one-time header check, a free grader is fine. If you want continuous assurance that no unauthorized or tampered script is running on your payment and login pages — without adding code to those pages — that is exactly what ScriptPatrol is built for. Start with a free scan to see your current picture.
See the scripts your WAF can’t
Run a free scan of any page — your A+ to F Security Score, every third-party script identified, and where the page sends data. No account, no card.