How to stop IntelliJ truncating output when I run a build?

By a popular request Override console cycle buffer size setting was added to the UI 9/14/16:

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Original answer for older versions:

Edit your IDEA_HOME\bin\idea.properties file, and increase this setting:

#-----------------------------------------------------------------------
# This option controls console cyclic buffer: keeps the console output size not higher than the specified buffer size (Kb). Older lines are deleted.
# In order to disable cycle buffer use idea.cycle.buffer.size=disabled
idea.cycle.buffer.size=1024

then restart IntelliJ.

This can (now) be edited in the Intellij IDEA settings.

This has probably been in Intellij IDEA for a while, and certainly is as of Intellij IDEA 15.

The problem increasing the console cylce buffer size is that you are likely to run out of heap space, and then you will need to bump up the max heap size. For an app that generates a very large amount of output it probably won't help as you will not have enough physical memory.

I would suggest instead that you capture the console output in a file.