Increase output buffer when running or debugging in PyCharm

My console output is exceeding PyCharm's buffer size in the Run output window. So when I scroll to the top after a test completes, I can't get all the way to the start of the console output. I can run the tests in an external terminal window and see all the output, but the integration with PyCharm is handy.

Is there a way to increase the buffer size of the PyCharm run output so I can retain all my logging output and scroll right to the top?

For PyCharm Community 2016.3 (Mac) you can increase the size of console buffer in the application Preference:

Yes, you can edit the idea.cycle.buffer.size setting within the bin/idea.properties file within the installation folder (or within the Application package on OS X).

Setting:

idea.cycle.buffer.size=disabled

disables the cyclic buffer.

See https://www.jetbrains.com/idea/help/file-idea-properties.html for details.

At least as of PyCharm Community Edition 5.0.3, IntelliJ does not recommend editing bin/idea.properties. From the URL mentioned above:

The file idea.properties, located in the bin directory of the IntelliJ IDEA installation folder, should not be edited. Instead of editing the original idea.properties, create file idea.properties in the location specified below, open it for editing and add the required properties.

I discovered an easy way to do that: from PyCharm, run Help->Edit Custom Properties. This opens an editor window on an empty file where you can make and save options. In my case the file was saved at %USERPROFILE%\.PyCharm50\idea.properties.

Also, rather than completely disable the circular buffer, you may want to increase it from its default of 1024k, e.g. to idea.cycle.buffer.size=2048

Though it's apparently missing in JetBrains' documentation, I found it necessary to exit and restart PyCharm before this took effect with PyCharm CE 5.0.3 under Windows 7 Pro.

BTW, the bin/idea.properties file (C:\Program Files (x86)\JetBrains\PyCharm Community Edition 5.0.3\bin\idea.properties on my system) is still a good place to find out what settings may be edited and their current values.

None of these answers worked for me to increase the size of the Run Tool Window buffer in community build 2021.1.

Using Help/Edit Custom properties and then adding the line:

terminal.buffer.max.lines.count = 20000000

Is the only thing that worked for me