jQuery 4.0 Drops Support for Older Browsers and Removes Deprecated APIs
jQuery 4.0, now in its beta phase, marks a significant shift in the popular JavaScript library by phasing out support for older browsers and removing several deprecated APIs. This update also introduces support for Trusted Types, enhancing security and compatibility with modern web standards.
One of the most notable changes in jQuery 4.0 is the discontinuation of support for older browser versions. Internet Explorer 10 and earlier, Edge Legacy, Firefox versions prior to 65, and iOS versions before 11 are no longer supported. This move is part of a broader trend to streamline jQuery’s compatibility and focus on more current technologies. The planned removal of support for Internet Explorer 11 in jQuery 5.0 further reflects this direction, aligning with the industry’s shift away from outdated browsers.
The update also addresses the handling of native browser behaviors. In jQuery 4.0, the library no longer overrides native browser functionality, meaning that all browsers, except Internet Explorer, will adhere strictly to the current World Wide Web Consortium (W3C) specifications. This change is aimed at reducing inconsistencies and improving cross-browser compatibility.
Several APIs have been removed in this release, including 13 that were previously deprecated. These APIs were either intended for internal use or have been replaced by native equivalents available in all supported browsers. Additionally, jQuery’s prototype Array methods—push, sort, and splice—have been removed and replaced with their native Array functions. This adjustment streamlines the library and encourages developers to use standard JavaScript features.
A new feature in jQuery 4.0 is the support for Trusted Types. This enhancement ensures that HTML wrapped in TrustedHTML can be safely used with jQuery methods, complying with the Content Security Policy’s require-trusted-types-for directive. This addition improves security by preventing certain types of vulnerabilities related to HTML injection.
Lastly, the slim build of jQuery 4.0 has been optimized, with the removal of default options and callbacks. This reduction contributes to a smaller file size and more efficient performance, further aligning with modern development practices and minimizing unnecessary overhead.
Overall, jQuery 4.0 represents a major update aimed at modernizing the library, enhancing security, and improving performance, while moving away from outdated technologies and deprecated features.