Linux based tool to compare .docx files character by character.
./dcx file1.docx file2.docx
This tool currently uses unzip package.
It's popular, so it can be easily obtained with any package manager.
This tool extracts contents of both files and compares their differences. Then it prints computed percentage. It shows the inner structure of each .docx file. If they have different files, then they are shown. And tool shows version of .docx file.