Click on the "Browse" button and choose the subtitle files to compare
from your hard drive, then click on "Compare".
Optionally, a third subtitle "base" file containing the original
transcription can be uploaded as well, in case you want to
simultaneously compare the differences between files and see how the
translation fares as compared to the original.
Should you decide to upload the original transcription, be aware of the fact that the original transcription
must have the same timestamps as the original file to compare.