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Dup vs Gemini 2: 5 duplicates Gemini can't find

May 24, 2026 · 6 min read

Gemini 2 (MacPaw) is the most-installed duplicate finder on macOS. It's polished, fast, and friendly. But it has three structural blind spots that leave 10–50 GB on the table for the average user.

This page shows what Gemini misses, why it misses, and what Dup does instead. No marketing — just a 2026 feature matrix and five concrete examples.

Feature matrix (May 2026)

1. The HEIC photo you exported as JPEG

You shot a photo on iPhone (HEIC, 2 MB). You exported it for a friend (JPEG, 4 MB). Both live in your library. Same image, two formats, twice the storage.

Gemini 2 compares images within a format. HEIC vs HEIC, JPEG vs JPEG. The pair never gets compared because they look like different file types. Dup computes a perceptual hash on the decoded pixels — format is irrelevant.

2. The 4K video and its 1080p export

Same source, different encoding: H.265 4K original, H.264 1080p compressed copy you uploaded somewhere, and a ProRes intermediate from editing.

Three files, same footage, ~12 GB combined. Gemini 2 ships exact-match video dedup only — a 1-byte difference and they're treated as unrelated. Dup uses vid_dup_finder_lib's perceptual video hashing to match across codecs and resolutions.

3. Every photo of the same person

Sometimes the duplicate is conceptual: 200 photos of your ex you'd like to remove from the Photos library without scrolling through 20,000 images.

Gemini 2 has no face detection. Dup's on-device face engine groups every photo and video by person. Pick the person, review the matches, delete. Faces never leave your Mac.

4. The screenshot from 2019 you've forgotten about

Storage categories — screenshots, screen recordings, burst photos, selfies — are not exact duplicates but they're the same value: stale content you'd reclaim if reminded. Gemini 2 doesn't surface them. Dup's storage cleanup mode does, and the quality analyzer surfaces blurry / dark photos as a separate axis.

5. Xcode DerivedData and 80 GB of node_modules

Not a duplicate per se, but dev caches are where most full-disk warnings actually originate. Gemini 2 is photo-and-document focused. Dup ships a one-click cleanup for Xcode DerivedData, npm/node_modules, Cargo target/, pip caches, Homebrew caches, with safe defaults and a review step.

Where Gemini still wins

Gemini 2 has the brand. It's been around longer, has more reviews, and ships on Setapp. If you're already paying for Setapp and need only exact-match photo dedup, it's fine.

If you want to find the duplicates Gemini doesn't see — cross-format, video across codecs, same-person photo groups, dev caches — that's what Dup is for.