When comparing Spectacle vs Greenshot (for Windows), the Slant community recommends Greenshot (for Windows) for most people. In the question“What are the best screen capture tools for Windows?” Greenshot (for Windows) is ranked 2nd while Spectacle is ranked 6th. The most important reason people chose Greenshot (for Windows) is:
Greenshot is licensed under GPL with source code available on [BitBucket](https://bitbucket.org/greenshot/greenshot).
Ranked in these QuestionsQuestion Ranking
Pro Free and open source
Spectacle is licensed under MIT with source code available on GitHub.
Pro Low footprint
Spectacle only uses up 18-19 MB of RAM, which means there is not much overhead by using this app.
Pro Simple hotkeys
Spectacle offers easy-to-remember preset hotkeys.
All windows in Spectacle can be controlled with keyboard shortcuts, so no mouse is needed. This makes for a fast way to control windows.
Pro Great UX
Spectacle is easy to use and configure. It's plug and play.
Pro Multi-monitor support
Pro Free and open source
Greenshot is licensed under GPL with source code available on BitBucket.
Pro Can capture an entire webpage
Instead of just capturing the visible portion of the page, this tool can capture all of the page in one image by scrolling through the page, taking images at set points and then stitching the images together.
Pro Allows annotating, highlighting and obfuscating screenshots
Pro Freezes screen when you capture
When you enter a capture mode, the screen content is preserved as it was when you started capturing.
Pro Can be quickly invoked with the print screen button
Pressing the print screen button will allow you to select the captured area.
Pro Classic UI design makes it easy to use.
Pro Selecting custom rectangle is the default
Easy to use selection tool with a magnifier to select only the part of the screen that you need.
Con Impossible to add new functions
While keyboard shortcuts can be changed for the available actions, there is no way to add custom actions which in turn limits the functionality of the app.
Con Breaks on macOS High Sierra / Chrome or Firefox
Doesn't support side by side windows.
Con Limited window sizing capabilities
You can use 1/2 of the screen vertically and horizontally (divide into 4 parts). You can also use the screen in thirds too, but only the left and right third: you can't use the 1/3 in the center. There is no way to do a more granular distribution.
Con Not maintained
The software is free, but no longer seems to be maintained.
Con Doesn't work with any Adobe products
There are some apps like Adobe Reader that do not work with Spectacle. Basically, any app with a heavily customized UI that breaks OS X accessibility will not work correctly under Spectacle.
Con This version only works on Windows, not Linux nor Mac
However, the same author now has a separate version of Greenshot for iOS, which is available (for a small fee) in the Mac App Store at https://itunes.apple.com/us/app/greenshot/id1103915944