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To download Kaleidoscope from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.


By Black Pixel


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Spot the differences. Merge in seconds.

With text merge, three-way merge, folder comparison, and now the ability to ignore whitespace-only differences, Kaleidoscope integrates perfectly with the version-control systems you already use.

Who says powerful developer tools can’t be beautiful too?

Praise for Kaleidoscope
"Kaleidoscope epitomizes the concept of “versatile software”: anyone can pick it up and use it, and the app will “scale” according to a user’s needs." - Federico Viticci,

"Kaleidoscope 2 is breeze. I wish I'd had something like Kaleidoscope when I wrote my first novel, and I'll be counting on it when I finally get around to writing the next one." - Rene Ritchie,

"It’s beautifully designed, fast and wonderful to use. It’s become an essential part of my toolkit already." - Matthew Panzarino, The Next Web

It's Part of Your Workflow
- Subversion, Git, Mercurial, Bazaar, and Perforce support
- Integrates as a fully-functional diff or merge tool
- Supported by a growing list of GUI source control management apps

Two-Way Text Comparison & Merging
- Three powerful display modes
- Super-fast diffing of lines and character-level changes
- Color coding to spot added, deleted, and changed text

Three-Way Merge
- Review code changes and resolve conflicts
- Intelligently auto-merges the right content

File & Folder Comparison
- Ultra-fast algorithm for finding differences in large folders
- Sort and filter down to what matters most
- Drill deeper into folders for more detailed comparisons
- Copy your preferred files across sources

Powerful Image Comparison
- Compare images side by side, stacked, or split
- Spot subtle pixel differences with a high contrast “difference mask”

Optimized for OS X Lion & Mountain Lion
- Beautiful, modern UI to feel at home on your Mac
- Full-Screen mode for focusing on your content
- Looks gorgeous on retina displays and works wonderfully with high-resolution graphics

"The new Kaleidoscope is great, and has awesome and committed people behind it. Devs and designers need this tool." - @SteveStreza

"I just bought Kaleidoscope app! It has already saved my time greatly once (by comparing SQL from clipboard). Thank you!" - @befive_info

"Kaleidoscope 2 is the best merging tool for the Mac, hands down. I finally don't miss BeyondCompare." - @stefankendall

What's New in Version 2.1

New Feature: Added support for ignoring whitespace (leading, trailing and line ending) in text comparisons.
New Feature: Added an indicator to display remaining unresolved conflicts in a merge document.

Text Scope
- Added dropdown menus on either side of Choose Left/Choose Right buttons to make “Choose Both” options more discoverable.
- Added better tooltips for the “Copy to” buttons when in Unified view.
- Fixed various issues with Dark Theme which made text difficult to read.
- Fixed issue where selecting different text scope views on one window could affect copy right/left buttons on other windows.
- Fixed issue where holding option to modify the behavior of copy right/left buttons on one window could affect other windows.
- Fixed issue that could prevent Kaleidoscope from picking up changes made to a document open in more than one window.
- Fixed issue that could prevent Kaleidoscope from picking up changes made to documents externally, especially on the MAS build.

Folder Scope
- Fixed issue where sometimes Folder Scope copies would not show up correctly after the copy had taken place.
- Fixed issue where Folder Scope would not pick up external additions of empty files or directories.

- Fixed issue that caused git integration to fail on 10.9 Mavericks.
- Fixed issue where ksdiff was sometimes not able to connect to Kaleidoscope after reboots with window restoration enabled.
- Fixed issue that where Kaleidoscope would not allow quitting when choosing “Review Conflicts” on a modified document.

General Improvements
- Updated Automator actions to categorize correctly in Automator.
- Added support for copy/paste shortcuts in the crash reporter window.
- Kaleidoscope now avoids saving files without changes.
- Kaleidoscope will now disallow edits to files that can be read but not written to (e.g. docx files).
- Kaleidoscope now better remembers size and position of your windows.
- Fixed issue that stopped the comparison windows from minimizing when double clicking their title bar.
- Fixed issue where the path bar area could fail to update correctly when switching tabs.
- Fixed issue where clicking the dock icon would not restore minimized documents.
- Fixed issue where dragging a group of files that were already open in Kaleidoscope could cause issues resulting in not all new files being added.
- Fixed issue that made it possible for the comparison window to grow vertically offscreen on 10.9 leaving you with a window you could not reposition afterwards.
- Fixed issue that made it impossible to bring up the open dialog by clicking on an empty tab when fullscreen in 10.9.
- Fixed issue where sometimes full-screen windows would not be full-screen.
- Fixed small visual issues with the Ignored Files dialog window.
- Fixed documentation issues with ksdiff help.
- Improved Help Documentation.
- Various performance and stability fixes.


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Customer Reviews

Mediocre performance and poor support, completely unusable in El Capitan

- Update (1 star) -
Kaleidoscope is completely unusable on El Capitan, and was already doing really badly on previous versions of OS X. It frequently fails to load up folder and file comparisons, and even when it is working, it often stops comparing and has to be completely restarted to get it working again. Folder comparisons sometimes show that files and folders have changes, then when opening them up there aren’t any differences. It’s horrendously bad and really shouldn’t be for sale anymore. There’s no way Apple would have authorized this app if it had to pass through a review today. It hasn’t been updated in 18 months, despite massive bugs. At this point, you’d have to be insane to spend money on this app.

- Previous Review (2 stars) -
I continue to be disappointed by Kaleidoscope. In general, it's only so-so as a diff tool. There are a number of things it mislabels as additions or modifications, and it's not great at separating groups of changes like it claims to. The bigger issue here is that it only offers a raw diff, so it's mostly useless for comparing two XML files that may have changed spacing and formating, but contain similar content.

One of the biggest problems is performance and lack of decent multi-threading. Whenever I compare large folders of a few hundred files each, the app freezes up for a very long time. Not only does it lock up the window loading these folders, but every window, regardless of what they are comparing.

There are also a lot of basic usability issues, especially regarding keyboard shortcuts and basic operations, that don't work correctly.

I've reported many of the issues and bugs I've seen to the developers, including screenshots, videos, and assorted other samples, but a lot of it has been dismissed as issues they're not interested in fixing. After 6 months without an update or even a simple bug fix, I've got a feeling they've abandoned the app but don't want to stop making sales. I would strongly recommend staying away from Kaleidoscope, even if a new version finally comes out.

Looks pretty, but lacks basic features

I’ve been an avid user of webstorm/phpstorm and use the merge / diff tools a lot. In wanting to try a different IDE, I choose Kaleidoscope, and have regretted the $70 purchase since.

Compared with the web/phpstorm merge tool:
- It is unable to do selective code merges (eg, you can’t click on an arrow to shift code from one pane to the other, you have to manually copy / paste it)
- In diff view, you cannot do in-place text editing
- Was unable to figure out how to have it perform ‘just use this file for the merge’

Save Diffs

Please add the feature where I can save diffs, such that, when I tap on the saved diff file, I would be presented with the diffs in Kaleidoscope.

View in Mac App Store
  • $69.99
  • Category: Developer Tools
  • Updated:
  • Version: 2.1
  • Size: 22.3 MB
  • Language: English
  • Seller:

Compatibility: OS X 10.7.3 or later, 64-bit processor

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