= Capturing Standard Output/Error

Since version 1.3, the JUnit Platform provides opt-in support for capturing output
printed to `System.out` and `System.err`. To enable it, set the
`junit.platform.output.capture.stdout` and/or `junit.platform.output.capture.stderr`
xref:running-tests/configuration-parameters.adoc[configuration parameter] to `true`. In addition, you may
configure the maximum number of buffered bytes to be used per executed test or container
using `junit.platform.output.capture.maxBuffer`.

If enabled, the JUnit Platform captures the corresponding output and publishes it as a
report entry using the `stdout` or `stderr` keys to all registered
`{TestExecutionListener}` instances immediately before reporting the test or container as
finished.

Please note that the captured output will only contain output emitted by the thread that
was used to execute a container or test. Any output by other threads will be omitted
because particularly when
xref:writing-tests/parallel-execution.adoc[executing tests in parallel] it would be impossible
to attribute it to a specific test or container.
