Frequently asked questions
Does DupliWalker modify my files while scanning?
No. Scanning reads. So does grouping, sorting, previewing and comparing. The only actions that change anything are explicit file operations you select and confirm — see safety model.
Can duplicates have different filenames?
Yes, and this is the point. DupliWalker matches on content, so a file that was renamed, moved, or downloaded twice under different names is still found. See what is a duplicate?.
Can I scan just one folder?
Yes. Add it as a Dupli folder and leave the Reference side empty. Every result will be Own — copies within that one location — and you choose which copy to keep in each group.
What is a Reference folder?
The folder holding copies you intend to keep. It nominates the keepers in advance, and cleanup acts on Dupli folders only — so your trusted library is not what gets removed. See Dupli and Reference folders.
Why is an entire folder shown as one result?
Because the entire folder was duplicated, and reporting it once is more useful than reporting each of its files separately. Expand it with View → Show All File Groups. See identical folders.
How much space will I actually recover?
Less than the total size of everything marked as duplicate, because one copy per group is kept. A group of three 1 GB files is 3 GB on disk and 2 GB reclaimable. Sort by size if space is your goal — a few large duplicates usually beat thousands of small ones.
What is the difference between Own and Common duplicates?
Own duplicates occur within one side — several copies inside your Dupli folders. Common duplicates occur in both your Reference and Dupli folders. A file can be both. Common is the safest to clean up, because the copy you are keeping is the one you nominated.
Can I undo a deletion?
Treat deletion as final. What happens to a deleted file depends on the platform you are running on, and this documentation will state the behaviour per platform once it has been verified for that platform rather than assumed. Until then, make sure the copy you are keeping is one you can reach — which is what a Reference folder is for.
Do I have to delete anything?
No. Scanning and reviewing are useful on their own — finding out that a folder was duplicated is often the whole answer. Leaving results unactioned costs nothing.
What happens if a file changes while a scan is running?
Results describe what was on disk when the file was read. If something changes underneath a running scan, rerun the search before acting on those results — particularly if a file operation then fails, which is the usual sign that what is on disk no longer matches what was found.
Some questions people ask are not answered here yet — including how DupliWalker handles your data, and exactly which features differ between the browser and desktop applications. Those answers are being verified against both shipping builds rather than written from expectation, and will be published when they are confirmed rather than before.