Where in Azure Portal can I find the logs of my Azure Functions?

Question

I deployed my Azure Functions project but I don´t know where to find the logs after my Azure functions got executed.

Is it possible to see the logs(Warning or Information) in Azure Portal while I´m debugging my Azure Functions in Visual Studio?

Answer 1

Hi @Kim Strasser ,

Thanks for the offline conversation. Glad the issue is resolved.

The setting:

AzureFunctionsJobHost__logging__logLevel__default=Warning

is an environment variable used by Azure Functions to control the default log level for the Functions host.

If you have a host.json setting for logLevel.default, this environment variable takes precedence in Azure App Settings.

Setting it to Warning helps reduce unnecessary Information or Debug logs, which can:

• Lower Application Insights costs
• Reduce noise in production logs

You can check couple of places in the Portal where you can watch the logs:

1. Log streaming (“live” console output)

• In the Azure Portal, navigate to your Function App
• In the left-hand menu under Monitoring, click Log stream
• You’ll see the real-time output (Information, Warning, Error) from your functions as they execute

2. Application Insights

• Make sure you’ve turned on Application Insights for your Function App (via the Instrumentation Key or Connection String in Configuration =>Application settings)
• Open the linked Application Insights resource, go to Logs, and run a query over the traces (or exceptions) table to see past invocations and log levels
• You can also use Live Metrics Stream for a near-real-time view of incoming telemetry

3. Monitor blade (invocation summary)

• In your Function App, click Monitor in the left menu to see a history of executions, durations, success/failures and link into Application Insights if enabled.

Note: if you're stepping through code locally in Visual Studio, those Debug.Write/ILogger outputs appear in your local console window, not in the Portal. You'll need to publish/deploy (or attach an Application Insights SDK locally) for the Portal blades above to pick them up.

Hope that helps!

Answer 2

In the Azure portal, function execution logs can be viewed in two main ways:

1. Built-in log streaming (per‑instance)
   1. Open the Azure portal and go to the Function App.
   2. In the Function App blade, go to Platform features (or Monitoring section, depending on UI).
   3. Select Log streaming under Monitoring.
   4. This shows a live stream of all log output (Information, Warning, Error, etc.) from the running functions on a single instance.
2. Live Metrics / Application Insights (recommended)
   1. Ensure the Function App is connected to Application Insights.
   2. In the Function App, open the linked Application Insights resource.
   3. Use Live Metrics Stream to see near real‑time logs and metrics from all instances.
   4. Use the normal Application Insights views and queries to analyze stored telemetry.

For local debugging from Visual Studio:

• When running the Functions project locally, logs are streamed directly to the local console (via Azure Functions Core Tools).
• When the same project is deployed and running in Azure, Visual Studio Code can attach to streaming logs using the command palette command Azure Functions: Start streaming logs, which connects to the Function App’s streaming logs in Azure.

These mechanisms allow viewing Warning/Information logs in near real time while the functions execute in Azure; local debugging logs are visible in the local console, and when connected to Azure streaming logs they can be observed from the development environment as well.

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References:

• Enable streaming execution logs in Azure Functions
• Monitor executions in Azure Functions
• Develop Azure Functions by using Visual Studio Code (programming-language-java)
• Develop Azure Functions by using Visual Studio Code (programming-language-powershell)
• Tutorial: Debugging CloudScript using Azure Functions with the Azure portal
• Tutorial: Debugging CloudScript using Azure Functions in the Azure portal