Try search by image browser-based OS-independent tool (Windows, Linux, Mac etc.), which I developed. The limitation is the browser type (works best for Chrome and Firefox, some browsers do not support folder selection or too slow parsing the file directory), the file read speed, type of images (browser-readable only), and available memory. But if
If you have a good PC, I would say it is possible to scan 50000-100000more than 100000 images without a problem.
In case of privacy concerns, it is possible to save and host the tool page locally (e.g. on http://localhost:8000/ with a local Python server). This way no information will pass to the Internet at all.