Hello, I have a similar problem: OSMFilter seems to produce way too large files! I start with a dataset for everything of germany, that has 63GB. Then I run osmfilter to filter for all historic objects. I end up with a filezize of 57GB! This sems way too big, I expected a smaller output when only looking for a small subset such as historic tags.

Furthermore, running ogr2ogr on the produced file to convert the 57GB osm file to shp leaves me with 290mb of data…

Does osmfilter output file have some unnecessary overhead or why is it so big and how can I fix that?

I use this commands if it helps:

osmfilter germany-latest.osm --keep-tags="all historic=" -o=germany-historic.osm

this gives me 63gb → 57gb
Way too big, no??