Third-party monitoring
Third-Party Script Monitoring
The average website loads 15-30 third-party scripts. Your payment form, analytics, chat widget, and ad tags all depend on someone else's servers. When one of them goes down or starts returning errors, your site stays "up" but critical features silently break. Sitewatch checks every external script on your pages and alerts you when something fails.
- Monitor analytics, chat, payment, and ad tag scripts
- Detect when scripts return errors, 404s, or wrong MIME types
- Know when third-party dependencies stop loading
Third-party script failure
Confirmed via 2-of-3 retries
Affected scripts
Recent activity
- Stripe.js -- 503 Service Unavailable6:00 AM
- Intercom widget -- MIME type text/html (expected JS)6:00 AM
- Google Analytics -- 200 OK6:00 AM
- HubSpot tracking -- 200 OK6:00 AM
Why it matters
Third-party scripts are your biggest blind spot
Payment form failures
When Stripe, PayPal, or Adyen scripts go down or return errors, your checkout breaks completely. Every minute is lost revenue -- and your uptime tool reports everything is fine because your server returns 200 OK.
Chat widget outages
Intercom, Drift, or Zendesk scripts fail silently. Support requests go unanswered. Conversion-driving conversations never happen. Nobody notices for hours or days.
Analytics data loss
When analytics scripts stop loading, you lose attribution data, conversion tracking, and campaign insights. Decisions get made on incomplete data for days before anyone notices the gap.
Silent breakage
A third-party script returning the wrong MIME type or a 404 breaks critical functionality while your site looks perfectly healthy. Without checking each script, these failures are invisible.
Dependency blindness
You control your code but not your vendors. A vendor pushes a bad update, retires an endpoint, or has an outage. Unless you are checking every script on every page, you find out from your customers.
Ad tag failures
Broken ad tags mean lost revenue for publishers. Tag manager misconfigurations and ad network outages go undetected without script-level monitoring.
15-30
Avg third-party scripts per site
2-of-3
Retry confirmation
Every script in your HTML
Coverage
What gets flagged
Third-party issues Sitewatch catches
Script loading failures
- Payment scripts returning error status codes (Stripe, PayPal, Adyen)
- Chat widget scripts failing to load (Intercom, Drift, Zendesk)
- Analytics scripts returning 404 or 5xx errors (GA, Segment, Mixpanel)
- Ad tags and tag manager scripts unavailable or erroring
Delivery and MIME type issues
- Scripts served with non-JavaScript MIME types (browsers block execution)
- Script URLs redirecting to error pages or unexpected destinations
- Scripts returning 404 or 410 after vendor updates or endpoint changes
- CDN-hosted third-party scripts serving wrong content types
How it works
How third-party script monitoring works
Discover all scripts
Sitewatch fetches your page and parses the HTML to find every script tag -- first-party and third-party. Every external script URL is extracted automatically.
Check availability and type
Each script gets a HEAD request to verify its HTTP status code and MIME type. A script returning 503, 404, or text/html instead of application/javascript is flagged.
Confirm with retries
Detected issues go through 2-of-3 retry confirmation. Transient vendor blips are filtered out. Only persistent failures create incidents.
Alert with context
Confirmed failures trigger alerts across your configured channels with the script URL, HTTP status code, MIME type, and which page is affected.
You cannot control vendor outages. You can control how fast you find out.
Free plan. No credit card. 2-minute setup.
The blind spot
Your site depends on scripts you do not control
| Feature | Without monitoring | Sitewatch |
|---|---|---|
| Script failure detection | Users report it (if you are lucky) | Caught on next check cycle |
| Availability checks | Unknown until someone complains | HTTP status and MIME type verified |
| Vendor outage awareness | Hours or days later | Detected in daily check or on-demand |
| MIME type validation | Not checked | Every script verified |
| False positive prevention | N/A -- you are not checking | 2-of-3 retry confirmation |
| Script inventory | Manual audit (if it happens at all) | Auto-discovered from your HTML every cycle |
Script failure detection
Availability checks
Vendor outage awareness
MIME type validation
False positive prevention
Script inventory
FAQ
Frequently asked questions
Sitewatch monitors every external script referenced in your page HTML -- analytics (Google Analytics, Segment, Mixpanel), payment forms (Stripe, PayPal), chat widgets (Intercom, Drift), ad tags, tag managers, and any other third-party JavaScript. Scripts are discovered automatically by parsing the HTML.
No. Sitewatch checks the HTTP status code and MIME type of each script -- verifying that it loads and is served as JavaScript. It does not download, hash, or compare script contents between checks. It catches availability failures and delivery errors, not content-level changes.
Sitewatch detects scripts returning error status codes (404, 5xx), scripts served with wrong MIME types (e.g., a CDN serving text/html instead of application/javascript), and scripts that have been removed or relocated. These are the most common ways third-party dependencies break your site.
When Stripe.js (or any script) returns an error status code or wrong MIME type, Sitewatch confirms the failure with 2-of-3 retries and sends an alert across your configured channels -- 6 channels including Slack, email, and PagerDuty. The alert includes the script URL, HTTP status code, and which page is affected.
No. Sitewatch monitors your pages externally using HTTP requests. It discovers and checks all scripts automatically by parsing the HTML -- no code changes, no tags to install, no vendor integrations required.
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