The latest version of jQuery included in WordPress can always be found on the WordPress GitHub Repository.
A surprising number of WordPress installations are still using jQuery 1.6.4 and even older. Sometimes it helps us realise the current state of things are not so bad by looking back over the shoulder and appreciating just how far things have progressed through the years. The following is a brief history of jQuery and WordPress.
WordPress & jQuery
On Tuesday, May 15, 2007, WordPress version 2.2 was released that consisted “mainly of bug-fixes, feature enhancements, and security fixes.” One of the feature enhancements listed was the announcement that jQuery library was being used for core JS:
Switched to jQuery for core JS, which is lighter and faster.
With each minor release WordPress has updated the jQuery library to the latest stable version. jQuery version 1.12.4 has been included with WordPress since WordPress 4.6 was released on August 16, 2016.
List of the jQuery library version that was included with each minor WordPress release:
- WordPress 5.1 includes jQuery 1.12.4
- WordPress 5.0 included jQuery 1.12.4
- WordPress 4.9 included jQuery 1.12.4
- WordPress 4.8 included jQuery 1.12.4
- WordPress 4.7 included jQuery 1.12.4
- WordPress 4.6 included jQuery 1.12.4
- WordPress 4.5 included jQuery 1.12.3
- WordPress 4.4 included jQuery 1.11.3
- WordPress 4.3 included jQuery 1.11.3
- WordPress 4.2 included jQuery 1.11.2
- WordPress 4.1 included jQuery 1.11.1
- WordPress 4.0 included jQuery 1.11.1
- WordPress 3.9 included jQuery 1.11.0
- WordPress 3.8 included jQuery 1.10.2
- WordPress 3.7 included jQuery 1.10.2
- WordPress 3.6 included jQuery 1.10.2
- WordPress 3.5 included jQuery 1.8.3
- WordPress 3.4 included jQuery 1.7.2
- WordPress 3.3 included jQuery 1.7.1
- WordPress 3.2 included jQuery 1.6.1
- WordPress 3.1 included jQuery 1.4.4
- WordPress 3.0 included jQuery 1.4.2
- WordPress 2.9 included jQuery 1.3.2
- WordPress 2.8 included jQuery 1.3.2
- WordPress 2.7 included jQuery 1.2.6
- WordPress 2.6 included jQuery 1.2.6
- WordPress 2.5 included jQuery 1.2.3
- WordPress 2.3 included jQuery 1.1.4
- WordPress 2.2 included jQuery (version not listed)
Why WordPress still uses jQuery v1.12.4
Since a large number of themes and plugins are using jQuery as loaded by WP core, WordPress can not simply update jQuery without risking major conflict issues. Here is a great thread on StackExchange with more info on this issue.