Platforms
- Online
Apps similar to Sassy-validation include Bootstrap, which is free and open source. Other options are Tailwind CSS, Semantic UI, Foundation and Material UI. You're spoiled for choice with CSS Frameworks like Sassy-validation: we list more than 50 alternatives for the web, self-hosting, Mac, Windows and Linux.
The Goldilocks Approach to Responsive Web Design - A good starting point for design that takes device resolution out of the equation.
A grid system for responsive web design. Includes folding columns, elastic gutters, a zoomable baseline grid, and a delightful grid overlay script.
Google's front-end web framework for building sites to the Material Design specification.



Less Framework is a CSS grid system for designing adaptive websites. It contains 4 layouts and 3 sets of typography presets, all based on a single grid.
The 960 Grid System is an effort to streamline web development workflow by providing commonly used dimensions, based on a width of 960 pixels. There are two variants: 12 and 16 columns, which can be used separately or in tandem.
Phonon is a front-end framework made with mobile and desktop in mind. It offers clear and neutral components that integrate best practices and ideas coming from well-known design styles.
Set column and gutter widths, choose the number of columns, and switch between pixels and percentages.
Webments is a collection of libre frameworks designed with scratch CSS using different design languages.



