Flask vs. Lumen vs. Slim

Flask is intended for getting started very quickly and was developed with best intentions in mind.

Laravel Lumen is a stunningly fast PHP micro-framework for building web applications with expressive, elegant syntax. We believe development must be an enjoyable, creative experience to be truly fulfilling. Lumen attempts to take the pain out of development by easing common tasks used in the majority of web projects, such as routing, database abstraction, queueing, and caching.

Slim is easy to use for both beginners and professionals. Slim favors cleanliness over terseness and common cases over edge cases. Its interface is simple, intuitive, and extensively documented — both online and in the code itself.