Feature Detection
Feature detection is a programming technique used to determine whether a web browser or runtime environment supports a specific feature, such as a JavaScript API, CSS property, or HTML element. It involves programmatically checking for the existence of a feature before using it, rather than relying on browser or version detection. This approach helps ensure cross-browser compatibility and graceful degradation by providing fallbacks or alternative implementations when features are unavailable.
Developers should use feature detection when building web applications that need to work across multiple browsers and devices with varying capabilities, such as in responsive web design or progressive web apps. It is essential for handling browser inconsistencies, supporting older browsers while leveraging modern features, and avoiding errors from unsupported APIs, particularly in JavaScript-heavy applications like single-page apps or interactive sites. Feature detection is preferred over browser sniffing because it is more reliable and future-proof as browsers evolve.