jQuery 4.0.0 Beta has been released after a long development process. This version includes bug fixes, performance improvements, and some breaking changes. One major change is the removal of support for IE less than 11. The team has also trimmed legacy code, removed deprecated APIs, and dropped support for complex behaviors. A comprehensive upgrade guide will be provided before the final release. The jQuery Migrate plugin will also be available to assist with the transition. Other notable changes include the removal of certain array methods, changes to focus and blur event order, and improved support for binary data and Trusted Types. The slim build of jQuery has also been updated to be smaller in size. The release is available on the jQuery CDN and npm package manager, with third-party CDNs hosting the final release later. Overall, compatibility is not expected to be an issue when upgrading from a jQuery 3.0+ version.
https://blog.jquery.com/2024/02/06/jquery-4-0-0-beta/