.CSS File Extension

Cascading Style Sheets

A CSS file formats HTML content. It defines size, color, font, and location of HTML elements. CSS files reduce work and code by consolidating display properties into a single file. To use a CSS file...

General Information

Title CSS File Extension
Extension .css
Full Form Cascading Style Sheets
File Type Style Sheet File
Developer World Wide Web Consortium (W3C)
MIME Type text/css

File Function

Primary Function Style webpage
Additional Functions Visual presentation
Features Cascading, Selectors, Media queries

File Characteristics

Quality Depends on design
Supports Layers N/A
Supports Transparency Yes
Editable Yes

Use Cases

Web Development Yes
User Interface Design Yes
Theming Yes

Security and Practices

Security Risks CSS Injection
Best Practices Validation, Sanitization

Historical/Version Information

Initial Release December 17, 1996
Latest Version CSS 3 (Snapshot 2021)

Associated Types

Similar Extensions .html, .scss, .less, .js

Software Compatibility

Software Usage Policy OS Compatibility
Google Chrome Free Windows, Mac, Linux, Android, iOS
Mozilla Firefox Free Windows, Mac, Linux, Android, iOS
Adobe Dreamweaver Subscription Windows, Mac
Visual Studio Code Free Windows, Mac, Linux