Use gdu to diff and compare directory usages.

Usage

Run:

gdu-diffdir /directory/a /directory/b

Or you can do steps manually (and optionally save intermediate results.

Export two scan results:

gdu -o old.gdu /some/directory
gdu -o new.gdu /some/directory

Generate diff:

gdu-diff old.gdu new.gdu > diff.gdu

Load and view the diff:

gdu -f diff.gdu