Iframe Tracking

Uncontrolled iframe loading — ads, widgets, payment forms, embedded content — can exhaust browser memory and crash the tab. CrashSense monitors iframe mutations in real-time to detect and report iframe-related resource exhaustion.

Enabling Iframe Tracking

import { createCrashSense } from '@crashsense/core';

const cs = createCrashSense({
  appId: 'my-app',
  enableIframeTracking: true,
});

How It Works

When enableIframeTracking is enabled, CrashSense uses a MutationObserver to watch the DOM for iframe additions and removals. It tracks:

• Total iframe count — all iframes currently in the DOM
• Cross-origin iframe count — iframes pointing to different origins (higher resource cost)
• Iframe origins — list of unique origins across all iframes

Reading Iframe State

Use getSystemState() to access current iframe metrics:

const state = cs.getSystemState();

console.log('Total iframes:', state.iframe?.totalCount);
console.log('Cross-origin:', state.iframe?.crossOriginCount);
console.log('Origins:', state.iframe?.origins);

Integration with Pre-Crash Warnings

When both enableIframeTracking and enablePreCrashWarning are enabled, iframe count contributes to warning levels:

Warning Level	Iframe Trigger
elevated	> 5 iframes
critical	> 10 iframes
imminent	> 15 iframes

const cs = createCrashSense({
  appId: 'my-app',
  enableIframeTracking: true,
  enablePreCrashWarning: true,
  enableMemoryMonitoring: true,
});

Crash Classification

When a crash occurs and iframe count is abnormally high, CrashSense may classify the crash as iframe_overload with contributing factors that include iframe count and memory correlation:

{
  category: "iframe_overload",
  confidence: 0.82,
  contributingFactors: [
    { factor: "high_iframe_count", weight: 0.9, evidence: "18 iframes detected (12 cross-origin)" },
    { factor: "high_memory_utilization", weight: 0.7, evidence: "Heap at 89% (470MB / 528MB)" },
  ]
}

Common Scenarios

• Ad-heavy pages: Third-party ad scripts that inject multiple iframes over time
• Embedded widgets: Chat widgets, social media embeds, video players
• Payment forms: Stripe, PayPal, and other payment processors use iframes
• SPA route changes: iframes from previous routes that are not properly cleaned up

TIP

Iframe tracking has minimal overhead — it uses a single MutationObserver on the document body and only processes IFRAME element mutations.