The problem: every "free" image converter wants your files
If you've ever needed to quickly convert a batch of photos to WebP or shrink a folder of PNGs before shipping them to production, you've probably run into the same annoyance I did: most "free online converters" require you to upload your files to a remote server first.
That's fine for a random screenshot. It's not fine when the images are:
Unreleased product shots under NDA
Client assets you're not supposed to redistribute






