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 Desktop | DuoBolt CLI | Gemini 2 |
|---|---|---|---|
| Platforms | macOS, Windows | macOS, Windows, Linux | macOS only |
| Interface | Desktop GUI | Terminal | Desktop GUI |
| Pricing model | $29.99 one-time, 2 seats | Free | $19.99/yr (App Store) · ~$99.95 lifetime, 1 Mac (macpaw.com) · Setapp from $9.99/mo |
| Hashing | BLAKE3 | BLAKE3 | Proprietary (no public detail) |
| Match type | Exact byte-for-byte | Exact byte-for-byte | Exact + similarity (fuzzy) |
| APFS clone awareness | Yes (1.4) | Yes (1.4) | No |
Scans ~/Library | Yes | Yes | No (sandbox restriction) |
| NAS / network volumes | Yes | Yes | Times out at TB scale |
| Safe deletion | Via system Trash | No deletion (read-only) | Via system Trash |
| Deletion history & restore | Yes | — | Limited |
| Move-to-archive flow | Yes (1.4) | — | No |
| Output formats | Visual UI | JSON, CSV, TXT | Visual UI |
| Automation / scripting | — | Yes | No |
| Public benchmarks | Yes | Yes | No |
| Account / telemetry | None | None | MacPaw / Setapp account |
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 1.4 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 need cross-platform or automation
Gemini 2 is macOS-only with no command-line interface. DuoBolt ships a desktop app for macOS and Windows, plus a CLI for macOS, Windows, and Linux with JSON/CSV output for pipelines.
When to Choose Gemini 2
Section titled “When to Choose Gemini 2”- You want visually similar photo detection (not byte-identical) — Gemini 2’s fuzzy matching is its real strength
- You’re cleaning up an Apple Photos library with deep catalog/album integration
- 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 1.4 introduced APFS clone awareness: 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 — like every other consumer duplicate finder — counts clones as recoverable space they aren’t.
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 only flags byte-for-byte identical files via cryptographic BLAKE3 hashing. Zero false positives by design — see why exact matters. For visually similar photos you want a different tool; for everything else, fuzzy matching introduces risk.
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.
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 CLI for macOS, Windows, and Linux. Desktop app for macOS and Windows.