You scan external drives
On a 797 GB external SSD over USB-C, DuoBolt finishes in 5m17s against dupeGuru’s 9m42s — 1.84×, with the bus limiting both tools.
DuoBolt vs dupeGuru — 11.5× Faster on Our Benchmarks
dupeGuru is a free, open-source duplicate finder, and its last release was in July 2022. DuoBolt is 11.5× faster across a source tree of 1.69 million files, where the result is decided by what each tool spends per file. On storage limited by the disk or the network instead, the two finish much closer together.
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. dupeGuru 4.3.1, its latest release, from July 2022. Lower times are better.
| Storage | DuoBolt | dupeGuru | DuoBolt advantage |
|---|---|---|---|
| Internal SSD — 394 GiB, 1.69M files | 38s | 7m17s | 11.5× faster |
| USB-C SSD — 797 GB | 5m17s | 9m42s | 1.84× faster |
| NAS over SMB — 1.09 TiB | 10s | 17s | Too close to call |
Key takeaway: dupeGuru’s disadvantage is what it spends per file, so it shows up where per-file work dominates. Across 1.69 million files it needs 7m17s against 38s. On an external SSD, where the bus limits both, it is 1.84× behind. On the NAS, DuoBolt’s own three passes varied by about ±30%, so 10s against 17s is not a gap worth claiming.
Feature Comparison
Section titled “Feature Comparison”| Feature | DuoBolt | dupeGuru |
|---|---|---|
| Platforms | macOS, Windows | macOS, Windows, Linux |
| Price | Free tier · $34.99 one-time | Free (open source) |
| Sold as a subscription | No | No |
| Hashing | BLAKE3 | xxHash (MD5 as a fallback) |
| Similar photos | Yes, with AI Curation | Yes (fuzzy match) |
| Adjustable similarity | Yes — five bands, Identical to Loosely similar | Yes — a filter-hardness slider |
| 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 |
| APFS clone awareness | Yes | No |
| NAS / network drives | Yes | Yes — within measurement of DuoBolt over SMB |
| Rescan cache | Yes — hashes and thumbnails, separate local and network thresholds | Yes (picture cache) |
| Re-runnable scan history | Yes — each scan’s full setup is stored and can run again | — |
| Safe deletion | Trash, archive, or copy | Send to Trash, with direct delete as an option |
| Review before removing | Mandatory Review Selection step, counting what would be left with no copy | A deletion-options dialog |
| Protected folders | Yes — files stay unselectable | Not documented |
| Recovers permanent deletions | Yes — rebuilt from a byte-identical copy, with the original dates and tags | — |
| Account / telemetry | None | None |
| Active development | Yes | Last release 4.3.1, July 2022 |
When to Choose DuoBolt
Section titled “When to Choose DuoBolt”You need speed on codebases
DuoBolt is 11.5× faster than dupeGuru across a source tree of 1.69 million files. The gap grows with file count rather than with bytes.
You want safe, auditable cleanup
Both tools send files to the Trash by default, so both are recoverable until you empty it. DuoBolt keeps going after that: every operation records each file’s path, dates, permissions and BLAKE3 hash, and Review & Restore rebuilds a file from a surviving byte-identical copy. That works after a permanent delete, and it is in the free tier.
When to Choose dupeGuru
Section titled “When to Choose dupeGuru”- You need a free, open-source tool
- Your scans are small, and speed is not the deciding factor
- You need similarity matching for music, which DuoBolt does not do
- You’re on Linux, which DuoBolt does not support
Weighing dupeGuru against the other free option instead? Czkawka vs dupeGuru has both measured side by side.
Where DuoBolt’s Time Goes
Section titled “Where DuoBolt’s Time Goes”dupeGuru hashes with xxHash, which is fast. The gap in the table is not the hash. DuoBolt was built around:
- BLAKE3 — a cryptographic hash, which xxHash is not
- Parallel I/O — streaming reads overlap disk access with hashing
- Prehashing — a partial hash first, so only matching candidates get a full-content read
What the measurements show is that the advantage grows with file count rather than with bytes. We have not profiled dupeGuru to say which part of its pipeline is the limit, and this page will not guess at one.
Related
Section titled “Related”Full Benchmark Results
All three storage tiers, compared against dupeGuru, Czkawka, Gemini 2 and Duplicate File Finder, with full methodology.
Download DuoBolt
Free to scan on macOS and Windows, with a free tier that also cleans.