When comparing Spectre vs Flutter, the Slant community recommends Spectre for most people. In the question“What is the best CSS framework?” Spectre is ranked 11th while Flutter is ranked 25th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Lightweight
Pro Clean
Very clean design compared to bootstrap.
Pro Responsive
Works well on any device.
Pro Mobile ready
Spectre can be used to create mobile websites easily. With all the regular built in elements (buttons, menus, grids etc).
Pro Simple
Contains only the basics, no extra fluff.
Pro Open source
Spectre is used through Github, and is open source.
Pro Open source
Pro Great developer tools debug/hotreload/analyser
Pro Based on Dart language
Dart is a Java like language, easy to learn and startup fast for millions of Java developers.
Pro A single codebase for iOS AND Android
Pro Fast
The developer's goal is to allow people to make apps running at 120 FPS.
Cons
Con Not actively developed
Con Still in development
According to the website, Flutter is still in its early stages of development.
Con Based on Dart language
Dart is a Java like language, easy to learn and startup fast for millions of Java developers. BUT if you have to learn it ... it's a con.
Con Dart is unpopular and never gained serious community traction like Kotlin or Java
Con Does not support 32-bit iOS devices
If you plan on targeting iPhone 5, 5C or earlier, you can forget about Flutter.
Con Google has a bad history with product loyalty
