When comparing Gemini 2 vs Kaleidoscope, the Slant community recommends Gemini 2 for most people. In the question“What is the best app for dealing with duplicate files for Mac?” Gemini 2 is ranked 1st while Kaleidoscope is ranked 4th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Ease of use through good UI design
Pro Finds similar photos and removes them in one go
Pro Simple UI
Kaleidoscope has a beautiful and simple UI. It displays the two files that are being compared side to side, highlighting all the differences in a way that's easy to understand.
Pro Diff within a line
When working in code, line-by-line diff can still be hard to spot small changes within the line. Kaleidoscope will highlight what has changed.
Pro Supports comparing folders
Pro Image difference viewer
Kaleidoscope supports image diff viewer in addition to git diff. It's able to find even the slightest changes between two versions of the same image.
Cons
Con Useful for pictures, but not for complex file/folder structures
Comparing two folders with fonts needs more time and interaction than doing it by hand.
Con One trick pony
Can't do things like merge, or only show orphans.
Con Mac OS only
Kaleidoscope is a Mac OS X only app.
Con Paid software
Kaleidoscope is not free, costing $69.99.