There are two built-in logger factories for writing log messages from the Optimizely Log API to .NET Diagnostics Trace; the `EPiServer.Logging.TraceLoggerFactory` and the `EPiServer.Logging.TraceSourceLoggerFactory`.

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Note

In Optimizely Digital Experience Platform (DXP), Optimizely logs are redirected into .NET Diagnostic Trace, as long as the code uses the Optimizely logging abstraction `EPiServer.Logging.LogManager`. If you are using log4net and deploying in Optimizely DXP, replace `log4net` with `EPiServer.Logging`. See also [Logging](🔗) for more information on switching logging APIs.

## EPiServer.Logging.TraceLoggerFactory

The `EPiServer.Logging.TraceLoggerFactory` logger redirects all log messages to diagnostics trace.

You enable `EPiServer.Logging.TraceLoggerFactory` like this:

Or from the** episerver.framework** section like this:

## EPiServer.Logging.TraceSourceLoggerFactory

The `EPiServer.Logging.TraceSourceLoggerFactory` redirects all log messages to diagnostics trace source. In this implementation each logger name has its own source switch trace.

You can enable the `EPiServer.Logging.TraceSourceLoggerFactory` like this:

Or from the **episerver.framework** section like this:

By default, the logging level is set to the **Error** level. If you need to log lower levels than the Error level you need to configure it in the **system.diagnostics** section like this:

## Register Logger Factory via configuration

To register a logger factory via configuration, you need to add the logger factory type in the **appSettings** section:

Or from **episerver.framework** section:

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Note

The **appsetting** section value always has a higher priority than the **episerver.framework** section value.