What exact matching catches — and what it can't
This tool finds rows whose chosen columns are the same after trimming, case-folding, and (in fuzzy mode) ignoring punctuation and email dot/plus variants. That catches re-imports, copy-paste doubles, and formatting drift — usually the bulk of the count, and worth removing.
What no key comparison can see: Jon Smyth at Acme and Jonathan Smith at ACME Industrial with different email addresses. Those need semantic matching — understanding that two records describe the same person. That's SmartMatch, and it's the reason CleanSmart exists: you review every suggested merge, export the clean file, and re-import it on your schedule.
Try it with nothing at stake
No CSV handy? Generate a test file with planted duplicates and an answer key, run it through this tool, and see exactly which planted problems exact matching catches and which it misses.