jQuery 4.0 Released

jQuery, one of the web’s most widely used JavaScript libraries, has released version 4.0.0 to mark its 20th anniversary. This major update brings a host of modernizations, including a migration to ES modules for seamless integration with contemporary build tools like Rollup, Vite, and Webpack. The release also drops support for Internet Explorer 10 and older, as well as other legacy browsers, while maintaining temporary support for IE11. Developers are encouraged to use native JavaScript features, as several long-deprecated APIs have been removed.

Security is a key focus in jQuery 4.0.0. The new version introduces Trusted Types support to help prevent DOM-based XSS attacks and strengthens AJAX security by requiring explicit data types for JSONP and script requests. The slim build is now even lighter, and the order of focus events has been updated to align with W3C specifications.

This release is especially significant for teams maintaining legacy applications, offering a more secure, lightweight, and future-proof library. The official migration guide and jQuery Migrate plugin aim to make the transition as smooth as possible for existing projects.