Top 12 Free CSS User Interface (UI Toolkits)

Metro UI CSS is a free CSS UI Kit to design and develop websites or user interface in the style of Windows 8 Metro UI. The UI framework is compatible with all major browsers such as IE 9+, Chrome, Opera, Safari, and Firefox and offers all common web UI elements such as popular tiles, images, notices, forms, buttons, and typography. – Metro UI CSS

UI.CSS is a simple UI toolkit to create minimalist, clean user interfaces for the web. It included CSS file with styles for all Web UI elements, including :hover and:active states. – UI.CSS

CSS UI Kit is a fully CSS3 coded UI toolkit. it included all basic UI elements from a search box, checkboxes, radio buttons to drop down buttons, paginations, and Audio player UI.

It works beautifully in Chrome and Safari, just expect some problems in IE, Firefox, and Opera. – CSS UI Kit

Designer CSS UI Kit has been designed and hand-coded from scratch in HTML5 taking advantage of modern CSS3 techniques.

it includes a range of common user interface elements and font stacks, which look beautiful in modern browsers and degrade gracefully in Internet Explorer. – Designer CSS UI Kit

CSS3 UI Kit is a set of CSS3 UI elements to create a clean, simple user interface for the web. The UI kit included Menus, form elements, and buttons. – CSS3 UI Kit

Icon Deposit CSS3 UI Kit included all required web UI elements from GUI switches to buttons, Radio buttons, and Checkboxes.

it also included Photoshop PSD file for those who want to edit the design or make the images bigger. Icon Deposit CSS3 UI Kit

Gumby Framework is a new responsive 960 Grid CSS framework to create responsive web layout pages quickly and easily in a natural, logical way.

The Grid system of the Gumby Framework is highly customizable and easily molded as per your design needs.

it’s easily adapted to any screen size or application. The possibilities are endless; the results are extraordinary – Gumby Framework UI Kit

Massive CSS3 UI Kit offer huge assortment of UI elements purely built with CSS3. There is only one image used for create dropdown arrow.no JavaScript, no extra markup required.

Every UI element has a disabled style which makes it look flat and transparent. – Massive CSS3 UI Kit

CSS Grid UI Set give you clean icons and solid Dark UI design. The UI kit based on HTML/CSS (preprocessed with LESS). – CSS Grid UI Set

Pure CSS UI Kit

Lion CSS UI Kit is a simple UI toolkit for web designer to prototype native apps for Mac OS X Lion.

The UI toolkit specially design for Webkit based browser, but should work mostly fine in any browser that supports gradients and flexboxes. – Lion CSS UI Kit

CSSUIKit is a simple UI kit for iOS devices. With this kit, Users can design stunning iOS apps mockup design. it included all UI elements from iOS to you, done entirely in CSS. – CSSUIKit