how to reduce disc space if we have 10,000 input test data files

We have 10,000 test cases each test case has a test input file XML. So there are 10,000 XML files which are taking a lot of disc space about 2GB.

we have converted all the XML files to JSON files. which reduce a significant amount of space.

My Question is?

Is there any tool or another way we can reduce the size without affecting the performance.