NestFiles vs Czkawka

At a glance

Why we built it this way

Duplicate finders are old software — most of them optimize for the same thing: find matches, show a list, let you delete. That model works, but it also means one wrong click can be permanent. NestFiles takes a slower path on purpose: every match is previewed, nothing is deleted outright, and every completed action can be traced back and undone. That trade-off — a bit less raw speed for a lot more safety margin — is the entire reason NestFiles exists instead of just using an existing tool.

The honest part

We measured this ourselves rather than guessing: on a 200,000-file test folder, Czkawka finished about 2.5x faster on a cold run and about 3x faster warm. If you're scanning huge libraries and speed is what matters most, Czkawka is a solid, free, open-source choice — we won't pretend otherwise.

NestFiles is built around a different priority: the seconds right before and after you delete something. Every match is previewed before anything moves, duplicates go to a reversible quarantine instead of straight to deletion, and supported operations can be restored later from local recovery records — nothing is ever overwritten. If that safety margin matters more to you than raw scan speed, that's the gap NestFiles is built to close. Full testing methodology — test date, exact NestFiles and Czkawka versions, hardware spec, and sample size — is available on request at support@verteletskysoftware.com.

Where NestFiles wins

Everything happens in this order: preview, explicit approval, then action — never the reverse. Duplicates go to a reversible quarantine, not straight to deletion. Organize actions are planned and shown before they're applied. And every completed quarantine or organize action can be restored later from a local manifest, not just "undo while the app is still open." If you've ever deleted the wrong file and regretted it, that's the gap NestFiles is built to close.

Where NestFiles falls short

We'd rather say this plainly than let you find out the hard way: NestFiles is closed source, so you can't audit the code yourself the way you can with Czkawka or dupeGuru. It's also measurably slower at real-world scale — see the numbers above. It doesn't (yet) match Czkawka's raw scan speed on huge libraries. If open-source transparency or maximum scan speed on massive libraries matters more to you than the safety model, Czkawka is a genuinely good choice.

Which one should you use?

• Huge libraries, want the fastest scan: Czkawka
• Want to inspect the source code yourself: Czkawka
• Want a safety net before files are touched: NestFiles
• Want to undo a cleanup after the fact: NestFiles

Neither answer is universally right — it depends on whether you're optimizing for scan speed on a huge one-time cleanup, or for a lower-stakes way to make duplicate cleanup part of your regular routine.

What NestFiles deliberately doesn't do

NestFiles is a duplicate finder and safe organizer — not a general PC cleaner. On purpose, it doesn't include a registry cleaner, temp-file cleaner, autostart manager, or any "boost your PC" feature. It won't delete anything without your explicit confirmation, won't upload anything to the cloud, and treats every fuzzy photo/audio/video match as review-only, never as an automatic action.

What about dupeGuru?

dupeGuru is another open-source, cross-platform duplicate finder with modes for exact files, photos, and music. We haven't run a direct speed benchmark against it the way we did with Czkawka, so we won't invent numbers here — what we can say is that its published feature set doesn't document a reversible quarantine or restore workflow, which remains NestFiles' core focus.

Beyond exact duplicates

NestFiles also has an opt-in review mode for photos, audio, and video that aren't byte-identical but look, sound, or play similarly — resized images, trimmed clips, re-encoded songs. In our own side-by-side tests against Czkawka's equivalent modes on real media, NestFiles matched every true audio duplicate pair where Czkawka's mode found about half, On video, an early test undercounted NestFiles' matches due to an unsupported file format (.ogv) — once fixed, both tools matched the same true pairs (4 of 6). On a separate photo library testing cropped-image recall, both tools matched every true pair (1.000/1.000) after we calibrated one detection threshold. These are small test sets, not a general performance claim — and on NestFiles' side, every fuzzy match stays review-only and is never quarantined automatically.