vendorprefixed

Vendor-prefixed, or vendorprefixed in its compact form, refers to features in CSS and other web technologies that are implemented in some browsers behind a vendor-specific prefix, such as -webkit-, -moz-, -ms-, or -o-. These prefixes let browser vendors expose experimental or non-standard features before they are standardized. A prefixed form can apply to properties, values, or API names, signaling that the feature may evolve or be removed as specifications change.

Common examples include -webkit-transform, -moz-transform, -ms-transform, and -o-transform; -webkit-border-radius; -webkit-animation; -ms-filter. When writing CSS, you may need to include prefixed versions to maintain compatibility with older browsers that have not yet implemented the unprefixed standard. Modern tooling such as Autoprefixer automates this process by reading a browserlist configuration and inserting only the prefixes required for the target environments.

Current relevance and best practices emphasize that most major browsers now support standard CSS properties without prefixes, reducing the need for vendor-prefixed forms in new projects. However, some properties or newer features may still require prefixes in older or niche environments. Best practices include avoiding reliance on prefixes for long-term maintenance, using progressive enhancement, and testing across target browsers. Employing automation and keeping tooling up to date helps manage compatibility while maintaining cleaner, more maintainable code.