What is Application Insights?

Application Insights, a feature of Azure Monitor, is an extensible Application Performance Management (APM) service for developers and DevOps professionals. Use it to monitor your live applications. It will automatically detect performance anomalies, and includes powerful analytics tools to help you diagnose issues and to understand what users actually do with your app. It's designed to help you continuously improve performance and usability. It works for apps on a wide variety of platforms including .NET, Node.js, Java, and Python hosted on-premises, hybrid, or any public cloud. It integrates with your DevOps process, and has connection points to a variety of development tools. It can monitor and analyze telemetry from mobile apps by integrating with Visual Studio App Center.

How does Application Insights work?

You install a small instrumentation package (SDK) in your application or enable Application Insights using the Application Insights Agent when supported. The instrumentation monitors your app and directs the telemetry data to an Azure Application Insights Resource using a unique GUID that we refer to as an Instrumentation Key.

You can instrument not only the web service application, but also any background components, and the JavaScript in the web pages themselves. The application and its components can run anywhere - it doesn't have to be hosted in Azure.

Application Insights instrumentation in your app sends telemetry to your Application Insights resource.

In addition, you can pull in telemetry from the host environments such as performance counters, Azure diagnostics, or Docker logs. You can also set up web tests that periodically send synthetic requests to your web service.

All these telemetry streams are integrated into Azure Monitor. In the Azure portal, you can apply powerful analytic and search tools to the raw data.

What's the overhead?

The impact on your app's performance is small. Tracking calls are non-blocking, and are batched and sent in a separate thread.

What does Application Insights monitor?

Application Insights is aimed at the development team, to help you understand how your app is performing and how it's being used. It monitors:

  • Request rates, response times, and failure rates - Find out which pages are most popular, at what times of day, and where your users are. See which pages perform best. If your response times and failure rates go high when there are more requests, then perhaps you have a resourcing problem.
  • Dependency rates, response times, and failure rates - Find out whether external services are slowing you down.
  • Exceptions - Analyze the aggregated statistics, or pick specific instances and drill into the stack trace and related requests. Both server and browser exceptions are reported.
  • Page views and load performance - reported by your users' browsers.
  • AJAX calls from web pages - rates, response times, and failure rates.
  • User and session counts.
  • Performance counters from your Windows or Linux server machines, such as CPU, memory, and network usage.
  • Host diagnostics from Docker or Azure.
  • Diagnostic trace logs from your app - so that you can correlate trace events with requests.
  • Custom events and metrics that you write yourself in the client or server code, to track business events such as items sold or games won.

Where do I see my telemetry?

There are plenty of ways to explore your data. Check out these articles:

Article description Image
Smart detection and manual alerts
Set up automatic alerts that adapt to your app's normal patterns of telemetry and trigger when there's something outside the usual pattern. You can also set alerts on particular levels of custom or standard metrics.
Alert sample
Application map
Explore the components of your app, with key metrics and alerts.
Application map
Inspect the execution profiles of sampled requests.
Screen capture shows execution profiles of sampled requests.
Usage analysis
Analyze user segmentation and retention.
Retention tool
Transaction search for instance data
Search and filter events such as requests, exceptions, dependency calls, log traces, and page views.
Search telemetry
Metrics Explorer for aggregated data
Explore, filter, and segment aggregated data such as rates of requests, failures, and exceptions; response times, page load times.
Mash up data from multiple resources and share with others. Great for multi-component applications, and for continuous display in the team room.
Dashboards sample
Live Metrics Stream
When you deploy a new build, watch these near-real-time performance indicators to make sure everything works as expected.
Live metrics sample
Answer tough questions about your app's performance and usage by using this powerful query language.
Analytics sample
Visual Studio
See performance data in the code. Go to code from stack traces.
Screenshot shows Exception Details in Visual Studio and an example of going to code from stack traces.
Snapshot debugger
Debug snapshots sampled from live operations, with parameter values.
Visual studio
Power BI
Integrate usage metrics with other business intelligence.
Power BI
Write code to run queries over your metrics and raw data.
Continuous export
Bulk export of raw data to storage as soon as it arrives.

How do I use Application Insights?


Install Application Insights in your app, set up availability web tests, and:

  • Check out the default application dashboard for your team room to keep an eye on load, responsiveness, and the performance of your dependencies, page loads, and AJAX calls.
  • Discover which are the slowest and most failing requests.
  • Watch Live Stream when you deploy a new release, to know immediately about any degradation.

Detect, Diagnose

When you receive an alert or discover a problem:

  • Assess how many users are affected.
  • Correlate failures with exceptions, dependency calls, and traces.
  • Examine profiler, snapshots, stack dumps, and trace logs.

Build, Measure, Learn

Measure the effectiveness of each new feature that you deploy.

  • Plan to measure how customers use new UX or business features.
  • Write custom telemetry into your code.
  • Base the next development cycle on hard evidence from your telemetry.

Get started

Application Insights is one of the many services hosted within Microsoft Azure, and telemetry is sent there for analysis and presentation. So before you do anything else, you'll need a subscription to Microsoft Azure. It's free to sign up, and if you choose the basic pricing plan of Application Insights, there's no charge until your application has grown to have substantial usage. If your organization already has a subscription, they could add your Microsoft account to it.

There are several ways to get started. Begin with whichever works best for you. You can add the others later.

Next steps

Get started at runtime with:

Get started at development time with:

Support and feedback