Question on using Fiddler with Katalon Studio (proxy.option)

Katalon Studio doesn’t provide HAR file with Web Testing, so I wanted to use Fiddler to capture transactions that Katalon Studio generates.

While Fiddler is running on the machine, I executed Katalon Test Suite from the UI (you need to change Proxy Option in Katalon Studio to use ‘System Proxy Configuration’) and transactions were captured in Fiddler.

However when I tried running the same test suite from commend line next, nothing is getting captured by Fiddler.

Could you please help how I can fix this?

Below are commands I tried. I tried HTTPS instead of HTTP for server type, localhost instead of for server address. Port I am using for fiddler is 8989.

katalon -noSplash -runMode=console -projectPath=“C:\Katalon Studio\FiddlerTest\FiddlerTest.prj” -retry=0 -testSuitePath=“Test Suites/FiddlerTest” -executionProfile=“default” -browserType=“Chrome” --config -proxy.option=MANUAL_CONFIG -proxy.server.type=HTTP -proxy.server.address= “” -proxy.server.port= “8989”

katalon -noSplash -runMode=console -projectPath=“C:\Katalon Studio\FiddlerTest\FiddlerTest.prj” -retry=0 -testSuitePath=“Test Suites/FiddlerTest” -executionProfile=“default” -browserType=“Chrome” --config -proxy.option=USE_SYSTEM -proxy.server.type=HTTP -proxy.server.address= “” -proxy.server.port= “8989”

I am not sure which version of Katalon you are using right now? As latest version and some previous version do create HAR files.

If you still want to use Fiddler, Configure Proxy in Katalon GUI and use that instance of Katalon


What is the configuration change that needs to be made to integrate Fiddler with Katalon studio.


Configuration depends on Fiddler listenining port and address. i.e. in my machine fiddler is lisening to hence below configuration as per screenshot.
make sure you select HTTPS if request is being sent by HTTPS

Katalon >> Windows >> Preference >> Katalon >> Proxy

Thank you. I will try it out