Application Insights JavaScript SDK (Web) for TypeScript

When to Use

Use this skill when you need instrument browser/web apps with the Application Insights JavaScript SDK (@microsoft/applicationinsights-web). Use for Real User Monitoring (RUM) — page views, clicks, AJAX/fetch dependencies, exceptions, custom events, and browser-side GenAI agent traces correlated to backend...

Real User Monitoring (RUM) for browser apps with @microsoft/applicationinsights-web. Auto-collects page views, AJAX/fetch dependencies, unhandled exceptions, and (with the Click Analytics plugin) clicks. Supports custom events, metrics, and GenAI agent traces that follow OpenTelemetry GenAI semantic conventions and correlate to backend spans via W3C Trace Context.

Distinct from azure-monitor-opentelemetry-ts, which is for Node.js server apps. This skill is for browser/web code (and React Native).

Before Implementation

Search microsoft-docs MCP for current API patterns:

• Query: "Application Insights JavaScript SDK setup"
• Query: "Application Insights JavaScript SDK configuration"
• Query: "Application Insights JavaScript framework extensions React Angular"
• Verify package version: npm view @microsoft/applicationinsights-web version

Packages

Installation

npm i --save @microsoft/applicationinsights-web
# Optional plugins (install only what you use):
npm i --save @microsoft/applicationinsights-clickanalytics-js
npm i --save @microsoft/applicationinsights-react-js @microsoft/applicationinsights-react-native @microsoft/applicationinsights-angularplugin-js

Typings ship with the package — no separate @types/... install needed.

Connection String

The browser SDK requires a connection string at init time. It ships in plaintext to clients — Microsoft Entra ID auth is not supported for browser telemetry. Use a separate App Insights resource with local auth enabled for browser RUM if you need to isolate it from backend telemetry.

# Vite / CRA / Next.js — expose to client via the public env prefix
VITE_APPINSIGHTS_CONNECTION_STRING="InstrumentationKey=...;IngestionEndpoint=https://...;LiveEndpoint=https://..."
NEXT_PUBLIC_APPINSIGHTS_CONNECTION_STRING="InstrumentationKey=..."

Quick Start (npm)

import { ApplicationInsights } from "@microsoft/applicationinsights-web";

export const appInsights = new ApplicationInsights({
  config: {
    connectionString: import.meta.env.VITE_APPINSIGHTS_CONNECTION_STRING,
    enableAutoRouteTracking: true,        // SPA route changes -> page views
    enableCorsCorrelation: true,          // propagate Request-Id / traceparent to cross-origin AJAX
    enableRequestHeaderTracking: true,
    enableResponseHeaderTracking: true,
    distributedTracingMode: 2,            // DistributedTracingModes.AI_AND_W3C — emit traceparent for backend correlation
    autoTrackPageVisitTime: true,
    disableFetchTracking: false,          // fetch() is auto-instrumented by default
    excludeRequestFromAutoTrackingPatterns: [/livemetrics\.azure\.com/i]
  }
});

appInsights.loadAppInsights();
appInsights.trackPageView();

Call loadAppInsights() exactly once, as early as possible (before user interactions you want tracked). Then trackPageView() for the initial load — when enableAutoRouteTracking is on, subsequent route changes are automatic.

Quick Start (SDK Loader Script)

Recommended when you want auto-updating SDK and zero build pipeline. Paste this as the first <script> in <head>:

<script type="text/javascript" src="https://js.monitor.azure.com/scripts/b/ai.3.gbl.min.js" crossorigin="anonymous"></script>
<script type="text/javascript">
  var appInsights = window.appInsights || function (cfg) {

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