You want the hash named
DuoBolt says what it computes — full-content BLAKE3, on every candidate, with no mode that trades verification for speed. A duplicate it reports has been confirmed byte for byte.
DuoBolt vs Nektony's Duplicate File Finder
Duplicate File Finder by Nektony is a free Mac App Store app with a paid Pro mode, listed on the store as Duplicate File Finder Remover. It is the closest competitor to DuoBolt on price: its lifetime unlock is $34.99, the same as DuoBolt Standard. On speed the two are closer than the rest of the field on an external disk and further apart everywhere else. The differences that matter most are not in the timings.
Benchmark Results
Section titled “Benchmark Results”All tests ran on an Apple M2 Max, macOS 27.0, on 20 September 2026, with each tool’s own cache cleared before every run, a 1 KB minimum file size and exact duplicates only. Duplicate File Finder 9.2.2, free tier, with Full-scale duplicate scan enabled. Lower times are better.
| Storage | DuoBolt | Duplicate File Finder | DuoBolt advantage |
|---|---|---|---|
| Internal SSD — 394 GiB, 1.69M files | 38s | 1m39s | 2.61× faster |
| USB-C SSD — 797 GB | 5m17s | 6m5s | 1.15× faster |
| NAS over SMB — 1.09 TiB | 10s | 54s | 5.4× faster |
Key takeaway: on an external SSD the bus limits both tools and the gap is 15%. It widens where per-file work decides the result, and widens furthest over a network, where every extra check costs a round-trip.
Why Full-scale mode is the one we measured
Section titled “Why Full-scale mode is the one we measured”Duplicate File Finder has a Full-scale duplicate scan setting, described in the app as adding “additional file checks” that “may reduce scan speed.” It was off on the installation we tested, and the difference is not small.
With it off, the app scanned the 797 GB external volume in 2m14s and reported
102 GB of duplicates across 124,969 files. That volume reads at 542 MB/s,
measured with dd on a 3 GiB file. Reading 102 GB of content — the minimum
needed to confirm those files are byte-identical, before counting the one copy
per group that stays — takes 3m8s at that rate. The scan finished in about two
thirds of that.
With Full-scale enabled the same scan took 6m5s, which is above that floor. That is the mode in the table, because it is the one measuring the same work DuoBolt does.
DuoBolt has no equivalent setting. Full-content BLAKE3 hashing is not optional, and there is no faster mode that skips it.
Feature Comparison
Section titled “Feature Comparison”| Feature | DuoBolt | Duplicate File Finder |
|---|---|---|
| Platforms | macOS, Windows | macOS only |
| Minimum OS | macOS 11 · Windows 10 | macOS 11 |
| Distribution | macOS: direct download or Homebrew, not sandboxed · Windows: Microsoft Store | Mac App Store, sandboxed |
| Price | Free tier · $34.99 Standard or $64.99 Pro — one-time, 2 seats, macOS + Windows | Free tier · Pro $34.99 lifetime, $14.99/yr or $7.99/mo (App Store in-app) |
| Sold as a subscription | No | Yes, alongside the lifetime unlock |
| Hashing | BLAKE3, named and documented | Not disclosed |
| Full-content verification | Always — there is no mode that skips it | “Full-scale duplicate scan”, a setting |
| Similar photos | Yes, with AI Curation | Yes |
| Similar audio | No | Yes |
| Merge folders | No | Yes (Pro) |
| Explains its photo picks | Yes — every measure is named | Not documented |
| Opens RAW files | Yes — CR2/CR3, NEF, ARW, RAF, ORF, RW2, DNG and more | Not documented |
| HEIC / AVIF | Yes (Windows needs two free Store extensions for previews) | Not documented |
| Apple Photos library | Yes (macOS) — reads the library, removes to Photos’ Recently Deleted | Yes, as its own scan; a folder scan does not descend into the .photoslibrary |
| APFS clone awareness | Yes (macOS) — reports reclaimable separately from total | Not documented |
| Protected folders | Yes — files stay unselectable | Skip List, applied at scan time |
| Recovers removals | Yes, in every tier including Free — rebuilt from a byte-identical copy | “Restore removed duplicates” is a Pro feature |
| Scans external volumes | Yes | Yes, with a macOS permission grant per volume |
When to Choose DuoBolt
Section titled “When to Choose DuoBolt”You need Windows too
One purchase covers macOS and Windows, two seats, with the same engine on both. Duplicate File Finder is macOS only.
You want a removal to be undoable
Review & Restore rebuilds a file from a surviving byte-identical copy, with its original dates and tags, and it works after the Trash is emptied. It is in the free tier. Restoring removed duplicates is a Pro feature in Duplicate File Finder.
When to Choose Duplicate File Finder
Section titled “When to Choose Duplicate File Finder”- You want similar audio detection, which DuoBolt does not do
- You want to merge the contents of two folders, not just remove duplicates
- You prefer to buy and update through the Mac App Store, with its refund and family-sharing rules
- Your Mac is your only machine and a monthly or yearly payment suits you better than a one-time one
Related
Section titled “Related”Full Benchmark Results
All three storage tiers, compared against Duplicate File Finder, Czkawka, dupeGuru and Gemini 2, with full methodology.
Undoing a deletion
How a removed file is rebuilt from a surviving copy, after the Trash is emptied.