Instrument web apps at runtime with Application Insights

You can instrument a live web app with Azure Application Insights, without having to modify or redeploy your code. If your apps are hosted by an on-premises IIS server, install Status Monitor. If they're Azure web apps or run in an Azure VM, you can switch on Application Insights monitoring from the Azure control panel. (There are also separate articles about instrumenting live J2EE web apps and Azure Cloud Services.) You need a Microsoft Azure subscription.

Screenshot of App Insights overview graphs containing information on failed requests, server response time, and server requests

You have a choice of three routes to apply Application Insights to your .NET web applications:

  • Build time: Add the Application Insights SDK to your web app code.
  • Run time: Instrument your web app on the server, as described below, without rebuilding and redeploying the code.
  • Both: Build the SDK into your web app code, and also apply the run-time extensions. Get the best of both options.

Here's a summary of what you get by each route:

Build time Run time
Requests & exceptions Yes Yes
More detailed exceptions Yes
Dependency diagnostics On .NET 4.6+, but less detail Yes, full detail: result codes, SQL command text, HTTP verb
System performance counters Yes Yes
API for custom telemetry Yes No
Trace log integration Yes No
Page view & user data Yes No
Need to rebuild code Yes No

Monitor a live Azure web app

If your application is running as an Azure web service, here's how to switch on monitoring:

  • Select Application Insights on the app's control panel in Azure.

    Set up Application Insights for an Azure web app

  • When the Application Insights summary page opens, click the link at the bottom to open the full Application Insights resource.

    Click through to Application Insights

Monitoring Cloud and VM apps.

Enable client-side monitoring in Azure

If you have enabled Application Insights in Azure, you can add page view and user telemetry.

  1. Select Settings > Application Settings
  2. Under App Settings, add a new key value pair:


    Value: true

  3. Save the settings and Restart your app.

The Application Insights JavaScript SDK is now injected into each web page.

Monitor a live IIS web app

If your app is hosted on an IIS server, enable Application Insights by using Status Monitor.

  1. On your IIS web server, sign in with administrator credentials.
  2. If Application Insights Status Monitor is not already installed, download and run the Status Monitor installer (or run Web Platform Installer and search in it for Application Insights Status Monitor).
  3. In Status Monitor, select the installed web application or website that you want to monitor. Sign in with your Azure credentials.

    Configure the resource where you want to see the results in the Application Insights portal. (Normally, it's best to create a new resource. Select an existing resource if you already have web tests or client monitoring for this app.)

    Choose an app and a resource.

  4. Restart IIS.

    Choose Restart at the top of the dialog.

    Your web service is interrupted for a short while.

Customize monitoring options

Enabling Application Insights adds DLLs and ApplicationInsights.config to your web app. You can edit the .config file to change some of the options.

When you re-publish your app, re-enable Application Insights

Before you re-publish your app, consider adding Application Insights to the code in Visual Studio. You'll get more detailed telemetry and the ability to write custom telemetry.

If you want to re-publish without adding Application Insights to the code, be aware that the deployment process may delete the DLLs and ApplicationInsights.config from the published web site. Therefore:

  1. If you edited ApplicationInsights.config, take a copy of it before you re-publish your app.
  2. Republish your app.
  3. Re-enable Application Insights monitoring. (Use the appropriate method: either the Azure web app control panel, or the Status Monitor on an IIS host.)
  4. Reinstate any edits you performed on the .config file.

Troubleshooting runtime configuration of Application Insights

Can't connect? No telemetry?

  • Open the necessary outgoing ports in your server's firewall to allow Status Monitor to work.

  • Open Status Monitor and select your application on left pane. Check if there are any diagnostics messages for this application in the "Configuration notifications" section:

    Open the Performance blade to see request, response time, dependency and other data

  • On the server, if you see a message about "insufficient permissions", try the following:
    • In IIS Manager, select your application pool, open Advanced Settings, and under Process Model note the identity.
    • In Computer management control panel, add this identity to the Performance Monitor Users group.
  • If you have MMA/SCOM (Systems Center Operations Manager) installed on your server, some versions can conflict. Uninstall both SCOM and Status Monitor, and re-install the latest versions.
  • See Troubleshooting.

System Requirements

OS support for Application Insights Status Monitor on Server:

  • Windows Server 2008
  • Windows Server 2008 R2
  • Windows Server 2012
  • Windows server 2012 R2
  • Windows Server 2016

with latest SP and .NET Framework 4.5

On the client side: Windows 7, 8, 8.1 and 10, again with .NET Framework 4.5

IIS support is: IIS 7, 7.5, 8, 8.5 (IIS is required)

Automation with PowerShell

You can start and stop monitoring by using PowerShell on your IIS server.

First import the Application Insights module:

Import-Module 'C:\Program Files\Microsoft Application Insights\Status Monitor\PowerShell\Microsoft.Diagnostics.Agent.StatusMonitor.PowerShell.dll'

Find out which apps are being monitored:

Get-ApplicationInsightsMonitoringStatus [-Name appName]

  • -Name (Optional) The name of a web app.
  • Displays the Application Insights monitoring status for each web app (or the named app) in this IIS server.
  • Returns ApplicationInsightsApplication for each app:

    • SdkState==EnabledAfterDeployment: App is being monitored, and was instrumented at run time, either by the Status Monitor tool, or by Start-ApplicationInsightsMonitoring.
    • SdkState==Disabled: The app is not instrumented for Application Insights. Either it was never instrumented, or run-time monitoring was disabled with the Status Monitor tool or with Stop-ApplicationInsightsMonitoring.
    • SdkState==EnabledByCodeInstrumentation: The app was instrumented by adding the SDK to the source code. Its SDK cannot be updated or stopped.
    • SdkVersion shows the version in use for monitoring this app.
    • LatestAvailableSdkVersionshows the version currently available on the NuGet gallery. To upgrade the app to this version, use Update-ApplicationInsightsMonitoring.

Start-ApplicationInsightsMonitoring -Name appName -InstrumentationKey 00000000-000-000-000-0000000

  • -Name The name of the app in IIS
  • -InstrumentationKey The ikey of the Application Insights resource where you want the results to be displayed.
  • This cmdlet only affects apps that are not already instrumented - that is, SdkState==NotInstrumented.

    The cmdlet does not affect an app that is already instrumented. It does not matter whether the app was instrumented at build time by adding the SDK to the code, or at run time by a previous use of this cmdlet.

    The SDK version used to instrument the app is the version that was most recently downloaded to this server.

    To download the latest version, use Update-ApplicationInsightsVersion.

  • Returns ApplicationInsightsApplication on success. If it fails, it logs a trace to stderr.

        Name                      : Default Web Site/WebApp1
        InstrumentationKey        : 00000000-0000-0000-0000-000000000000
        ProfilerState             : ApplicationInsights
        SdkState                  : EnabledAfterDeployment
        SdkVersion                : 1.2.1
        LatestAvailableSdkVersion : 1.2.3

Stop-ApplicationInsightsMonitoring [-Name appName | -All]

  • -Name The name of an app in IIS
  • -All Stops monitoring all apps in this IIS server for which SdkState==EnabledAfterDeployment
  • Stops monitoring the specified apps and removes instrumentation. It only works for apps that have been instrumented at run-time using the Status Monitoring tool or Start-ApplicationInsightsApplication. (SdkState==EnabledAfterDeployment)
  • Returns ApplicationInsightsApplication.

Update-ApplicationInsightsMonitoring -Name appName [-InstrumentationKey "0000000-0000-000-000-0000"]

  • -Name: The name of a web app in IIS.
  • -InstrumentationKey (Optional.) Use this to change the resource to which the app's telemetry is sent.
  • This cmdlet:
    • Upgrades the named app to the version of the SDK most recently downloaded to this machine. (Only works if SdkState==EnabledAfterDeployment)
    • If you provide an instrumentation key, the named app is reconfigured to send telemetry to the resource with that key. (Works if SdkState != Disabled)


  • Downloads the latest Application Insights SDK to the server.

Questions about Status Monitor

What is Status Monitor?

A desktop application that you install in your IIS web server. It helps you instrument and configure web apps.

When do I use Status Monitor?

  • To instrument any web app that is running on your IIS server - even if it is already running.
  • To enable additional telemetry for web apps that have been built with the Application Insights SDK at compile time.

Can I close it after it runs?

Yes. After it has instrumented the websites you select, you can close it.

It doesn't collect telemetry by itself. It just configures the web apps and sets some permissions.

What does Status Monitor do?

When you select a web app for Status Monitor to instrument:

  • Downloads and places the Application Insights assemblies and .config file in the web app's binaries folder.
  • Modifies web.config to add the Application Insights HTTP tracking module.
  • Enables CLR profiling to collect dependency calls.

Do I need to run Status Monitor whenever I update the app?

Not if you redeploy incrementally.

If you select the 'delete existing files' option in the publish process, you would need to re-run Status Monitor to configure Application Insights.

What telemetry is collected?

For applications that you instrument only at run-time by using Status Monitor:

  • HTTP requests
  • Calls to dependencies
  • Exceptions
  • Performance counters

For applications already instrumented at compile time:

  • Process counters.
  • Dependency calls (.NET 4.5); return values in dependency calls (.NET 4.6).
  • Exception stack trace values.

Learn more


Next steps

View your telemetry:

Add more telemetry: