Nothing is hashed that cannot match
Files are partitioned by size first, then filtered by a head-and-tail prehash. A file with no possible partner is never read in full.
Overview
DuoBolt finds two different things, and the difference is worth getting straight before anything else.
Duplicate files Byte-for-byte identical copies. Verified by a full BLAKE3 hash — there is a right answer, and DuoBolt gives it.
Similar photos Shots that look alike. Bursts, exports, re-saves. A judgement, so DuoBolt shows its reasoning and leaves the call to you.
Everything else — reviewing, removing, restoring — is shared between the two.
Start here
Section titled “Start here” Installation macOS and Windows, under a minute
Desktop Guide The app end to end: pick folders, scan, review, clean
How duplicate detection works
Section titled “How duplicate detection works”Every match is confirmed
Anything reported as a duplicate has been verified by a full-content BLAKE3 hash. Names, dates and folders play no part in it.
Nothing moves without you
Marking is not removing. Every batch goes through Review Selection, and Operations History can put files back afterwards.
Some folders are off the table
Protected folders make files unselectable — the checkbox refuses rather than warning you after the fact.
Removing files
Section titled “Removing files”The four operations, what each one costs you, and how to undo them.
The four operations Trash, delete, archive, copy — and which are reversible
Review Selection The screen between marking files and removing them
Protected folders Folders that can never lose a file
History and restore Every scan and every operation, written down — and reversible
Reference
Section titled “Reference” Core Concepts The detection pipeline, stage by stage
BLAKE3 in DuoBolt Why this hash, and what it guarantees
Performance Benchmarks Measured against Czkawka, dupeGuru, and Gemini 2
DuoBolt for NAS Network volumes, caching, and what to exclude
KB vs KiB — File Size Units Why DuoBolt reports KiB, MiB, and GiB
FAQ Hashing, safety, NAS, APFS clones, performance
Changelog Release notes and version history