You scan large libraries or NAS
Gemini 2 timed out on both 1 TB NAS tests in our benchmarks. DuoBolt finishes the same scan in 64 seconds cold, 20 seconds warm — and keeps going on multi-TB datasets.
DuoBolt vs Gemini 2 — Speed & Feature Comparison
Gemini 2 (MacPaw) is one of the most polished consumer duplicate finders for macOS. It’s well-designed and easy to use, but its scan engine is built for Photos.app-style libraries — not codebases, sandboxed system folders, or terabyte-scale NAS volumes. In our benchmark suite, DuoBolt is up to 5.7× faster on local files, and completes scans where Gemini 2 either timed out or failed on permissions.
Benchmark Results
Section titled “Benchmark Results”All tests ran on Apple Silicon M1 Pro, macOS 26.1, with cleared caches and back-to-back execution. Lower times are better. Timeout = exceeded 15 minutes without completing. Failed = permission errors or refused to scan.
Gemini 2 was run in duplicates-only mode (its similarity detection was disabled) so the comparison only measures byte-identical duplicate detection — the workload both tools are designed to do.
| Dataset | DuoBolt | Gemini 2 | DuoBolt advantage |
|---|---|---|---|
| Design Projects (13.17 GB) | 1s | 5.5s | 5.5× faster |
| Codebase (37.92 GB) | 3s | 17s | 5.7× faster |
| Codebase + Library (large) | 24s | Failed | — |
| NAS Cold — 1.01 TB | 64s | Timeout | — |
| NAS Warm — 1.01 TB | 20s | Timeout | — |
Key takeaway: Gemini 2 is competitive on small, well-structured datasets but breaks on the workloads power users actually care about. It timed out on both NAS tests (cold and warm) and refused to scan ~/Library due to its sandbox model. DuoBolt completed every dataset, including the 1 TB Synology snapshot in 64 seconds cold.
Feature Comparison
Section titled “Feature Comparison”| Feature | DuoBolt | Gemini 2 |
|---|---|---|
| Platforms | macOS, Windows | macOS only |
| Minimum OS | macOS 11 · Windows 10 | macOS 10.10 |
| Pricing model | Free tier · $34.99 Standard or $64.99 Pro — one-time, 2 seats, macOS + Windows | $19.99/yr (App Store) · one-time €44.95 for 1 Mac, €66.95 for 2, €99.95 for 5 (macpaw.com) · Setapp from $9.99/mo |
| Sold as a subscription | No | Yes, from $1.95/mo — alongside a perpetual license |
| Hashing | BLAKE3, named and documented | Not disclosed |
| Match type | Exact byte-for-byte, plus similar photos | Exact + similarity (fuzzy) |
| Adjustable similarity | Yes — five bands, Identical to Loosely similar | Not disclosed |
| Reads RAW directly | 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, with albums — cannot Trash from it directly |
| Explains its photo picks | Yes — every measure is named | No |
| APFS clone awareness | Yes | No |
Scans ~/Library |
Yes | No (sandbox restriction) |
| NAS / network volumes | Yes | Times out at TB scale |
| Rescan cache | Yes — hashes and thumbnails, separate local and network thresholds | Not disclosed |
| Re-runnable scan history | Yes — each scan’s full setup is stored and can run again | No |
| Safe deletion | Trash, archive, or copy | Via system Trash |
| Protected folders | Yes | — |
| Recovers permanent deletions | Yes — rebuilt from a byte-identical copy, with the original dates and tags | No — only what is still in the Trash |
| Public benchmarks | Yes | No |
| Account / telemetry | None | MacPaw / Setapp account |
Where Gemini 2 wins on this table. It runs on Macs going back to macOS 10.10, where DuoBolt needs macOS 11. And inside the Photos library it knows about albums, which DuoBolt does not read: a scan there is about the photos themselves — their copies, their imports, their favorites and edits — not about where you filed them.
On price, like for like. Both tools sell a perpetual license, so compare the same thing: two machines, bought outright. Gemini 2 is €66.95 for two Macs — roughly $77. DuoBolt Standard is $34.99 for two seats, and DuoBolt Pro, which adds the entire look-alike photo engine and AI Curation on top, is $64.99. Our most expensive tier costs less than their two-Mac license, and a DuoBolt license covers Windows machines as well — Gemini 2 is macOS only.
MacPaw prices checked 16 August 2026 on the macpaw.com store; euro figures converted at approximately 1.16 USD/EUR. Both vendors change prices, so check the current figure before relying on it.
When to Choose DuoBolt
Section titled “When to Choose DuoBolt”You need to scan ~/Library or other system folders
Gemini 2 runs sandboxed and can’t access ~/Library — a major source of
duplicate caches, app data, and stale build artifacts. DuoBolt scans these
areas without restriction.
You want honest disk-space accounting
DuoBolt detects APFS clone groups (e.g., cp clones, Time Machine snapshots,
build caches) so the “recoverable space” number reflects what your disk
actually frees. Gemini 2 doesn’t distinguish clones from real duplicates.
You are not only on a Mac
Gemini 2 is macOS-only. DuoBolt runs on macOS and Windows with the same engine, the same results, and one license covering two machines.
When to Choose Gemini 2
Section titled “When to Choose Gemini 2”- You’re cleaning up an Apple Photos library by album, inside the Photos app itself
- You’re already a Setapp subscriber and the bundle works for your workflow
- Your scans are small, local, and well-structured (no NAS, no
~/Library, no cross-platform needs) - You prefer Gemini 2’s animated Smart Selection experience over a precision-first interface
Why DuoBolt Performs Better at Scale
Section titled “Why DuoBolt Performs Better at Scale”Gemini 2 is optimized for the median Mac user’s photo and music libraries. DuoBolt was designed around three constraints that consumer-grade scanners don’t optimize for:
- Per-root parallelism — DuoBolt keeps every CPU core busy across multiple scan roots simultaneously, instead of serializing through one filesystem traversal. This is what makes the 5–6× gap on local files and the difference between completing and timing out on NAS.
- Streaming, chunked I/O — reads overlap with hashing so the CPU never waits for slow disks. On NAS volumes where I/O latency dominates, this is the difference between 64 seconds and a 15-minute timeout.
- No sandbox — DuoBolt is distributed directly (not via the Mac App Store) so it can scan
~/Library, external drives mounted by other users, and system locations without permission walls. Gemini 2’s sandbox is a UX win for casual users and a hard ceiling for power users.
On top of speed, DuoBolt is APFS clone-aware: when files share storage at the filesystem level (Time Machine snapshots, cp clones, Xcode caches), DuoBolt reports both “recoverable” and “total” so you know what your disk will actually free. Gemini 2 does not offer a clone-aware figure, so a space estimate that includes cloned files will overstate what deleting them frees.
For full methodology, hardware details, and the third-party comparisons, see the benchmark page.
Match Type: Exact vs Similarity
Section titled “Match Type: Exact vs Similarity”The single biggest difference between the two tools isn’t speed — it’s what they consider a “duplicate.”
- Gemini 2 mixes exact matches with similar matches: photos taken seconds apart, music files re-encoded at different bitrates, near-identical exports. Useful for cleaning up a photo library, dangerous if you mistake a “similar” match for an exact one.
- DuoBolt runs two engines and keeps their verdicts apart. Duplicate files are flagged only when they are byte-for-byte identical, proven by cryptographic BLAKE3 hashing — zero false positives by design, see why exact matters. Look-alike photos are a separate engine that never uses the word identical: it groups by what the picture shows, tells you how tightly the group matched, and ranks each group while naming what it measured.
The difference is not that one tool does similarity and the other does not. It is that DuoBolt will not call a similarity verdict a duplicate.
If you’ve ever clicked “delete” on a Gemini 2 group and worried whether the matches were actually identical, that’s the gap. DuoBolt removes the worry by removing the ambiguity.
Getting a File Back After It Is Gone
Section titled “Getting a File Back After It Is Gone”Gemini 2’s safety net is the Trash: files go there, and you drag them out again if you were wrong. Empty the Trash, or delete permanently, and that is the end of it. MacPaw’s own FAQ says so.
DuoBolt’s safety net is not the Trash, and does not depend on it.
Every operation writes a journal row per file before the file goes away: its path, size, modified and created dates, permissions, extended attributes, and the BLAKE3 hash of its contents. To bring a file back, DuoBolt looks for a file still on disk with that same hash — a surviving copy of the very bytes — copies it to the original path, and puts the recorded identity back on it.
That is a reconstruction, not an undelete, and the difference cuts both ways:
- It works after the Trash has been emptied, and after a permanent delete, which no Trash-based restore can offer.
- It needs a surviving copy. Remove the last file holding those bytes and they are gone; DuoBolt says so on the screen rather than offering a button that would fail.
Three rules keep it honest. Eligibility is decided by content hash, never by
group, so a photo is never rebuilt from a look-alike neighbor. The dates, tags
and permissions come from the recorded original, never from the surviving copy,
which has its own. And nothing is ever overwritten: if something occupies the
original path, the file lands beside it as name (restored).ext.
This is in every tier, including the free one. See History and restore.
Related
Section titled “Related”Full Benchmark Results
All five datasets compared against Gemini 2, Czkawka, and dupeGuru with full methodology.
Exact duplicate file finder
Why DuoBolt only flags byte-for-byte matches — no name shortcuts, no fuzzy matching, no false positives.
Download DuoBolt
Free to scan on macOS and Windows, with a free tier that also cleans.