# How to use Logback in Katalon Studio? **URL:** \ **Category:** Web Testing\ **Tags:** katalon-studio\ **Created:** [May 8, 2020, 9:33am UTC](https://forum.katalon.com/t/how-to-use-logback-in-katalon-studio/43234 "2020-05-08T09:33:14Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![kazurayam](https://dub1.discourse-cdn.com/katalon/user_avatar/forum.katalon.com/kazurayam/32/333_2.png) [@kazurayam](https://forum.katalon.com/u/kazurayam)\ **Post date:** [May 8, 2020, 10:33am UTC](https://forum.katalon.com/t/how-to-use-logback-in-katalon-studio/43234/2 "2020-05-08T10:33:09Z")
Katalon Studio uses Logback already for its own use. If you are willing to develop a Custom Keyword, you can customize the way how KS uses Logback. See the following post: > [@Cleaning up output from Console](http://forum.katalon.com/t/cleaning-up-output-from-console/43210/2): > > Can we control if println appears on the Log Viewer, No, I don’t think it is possible. or is that locked to com.kms methods like KeyWordUtil only? Yes, almost. What determines if something gets displayed on the Log Viewer? [com.kms.katalon.core.util.KeywordUtil](https://github.com/katalon-studio/katalon-studio-testing-framework/blob/master/Include/scripts/groovy/com/kms/katalon/core/util/KeywordUtil.java) calls [com.kms.katalon.core.logging.KeywordLogger](https://github.com/katalon-studio/katalon-studio-testing-framework/blob/master/Include/scripts/groovy/com/kms/katalon/core/logging/KeywordLogger.java), where you can find ultimately org.slf4j.Logger is used.The LogViewer in the KS GUI seems displaying the logs recorded through the SLF4J logging infrastructure. Therefore, any … though it is not very easy … --- _[View the full topic](https://forum.katalon.com/t/how-to-use-logback-in-katalon-studio/43234)._