Duplicate files · Where it looks and what it skips
Why weren't my small files checked for duplicates?
Short answer: By default only files of 1 MB or more are compared, because tiny files take long to check and free little space. Turn on Include small files in the Duplicates window header and scan again to compare every file, however small.
By default the duplicate finder compares only files of 1 MB or more — the ones worth reclaiming. Comparing thousands of tiny files takes much longer and usually frees only kilobytes.
To compare everything, turn on Include small files in the header of the Duplicates window, then click Scan now. It's slower, and on a cloud account it means reading the full list of files.
If every file in a source is under the limit, the window says so plainly — for example "Nothing … was large enough to compare" — rather than claiming there are no duplicates. Empty files are never grouped, even with the switch on, because removing them frees nothing.