IE 11 Support Phase Out Plan

After recent research and discussion, a decision to drop Internet Explorer 11 support in WordPress was reached. However, the timing for this change was undetermined when the summary post was published.

After discussing with several contributors, the decision has been made to move ahead with officially removing IE11 support in WordPress 5.8.

Note: This change will only affect WordPress and it’s built-in features. For your site visitors, any pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the Plugin Directory or can be cost-based plugin from a third-party or theme you may be using, which was made with support for IE11 in mind, should still look and feel as if nothing changed.

Phase-Out Plan

IE11 support will be removed in two phases.

Phase 1: WordPress 5.8

For 5.8, the following steps will be taken:

  • Update the `browserslist` for the `package.jsonJSON JSON, or JavaScript Object Notation, is a minimal, readable format for structuring data. It is used primarily to transmit data between a server and web application, as an alternative to XML.` file in `trunktrunk A directory in Subversion containing the latest development code in preparation for the next major release cycle. If you are running "trunk", then you are on the latest revision.`.
  • Run the build process to update generated CSSCSS Cascading Style Sheets..
  • Update the `browserslist` in the GutenbergGutenberg The Gutenberg project is the new Editor Interface for WordPress. The editor improves the process and experience of creating new content, making writing rich content much simpler. It uses ‘blocks’ to add richness rather than shortcodes, custom HTML etc. repository to remove IE11 support from built CSS and JSJS JavaScript, a web scripting language typically executed in the browser. Often used for advanced user interfaces and behaviors..

This will effectively remove IE11 support in the blockBlock Block is the abstract term used to describe units of markup that, composed together, form the content or layout of a webpage using the WordPress editor. The idea combines concepts of what in the past may have achieved with shortcodes, custom HTML, and embed discovery into a single consistent API and user experience. editor and all generated CSS files used within the adminadmin (and super admin).

A TracTrac An open source project by Edgewall Software that serves as a bug tracker and project management tool for WordPress. ticketticket Created for both bug reports and feature development on the bug tracker. will be opened to discuss whether IE11 specific polyfills should continue to be enqueued in WordPress 5.8. Even if polyfills are not loaded, they will remain bundled with CoreCore Core is the set of software required to run WordPress. The Core Development Team builds WordPress. in case plugins or themes wish to continue loading them.

New features added in 5.8 or later do not need to be tested on or support IE11.

Phase 2: WordPress 5.9 and beyond

Because most of the code in WordPress Core targeting specific browsers maintained manually (not compiled or run through a build process), individual tickets should be created to evaluate removing each instance of IE11 specific code.

These tickets will not be considered in 5.8 unless a committercommitter A developer with commit access. WordPress has five lead developers and four permanent core developers with commit access. Additionally, the project usually has a few guest or component committers - a developer receiving commit access, generally for a single release cycle (sometimes renewed) and/or for a specific component. or release squad member feels it is a blockerblocker A bug which is so severe that it blocks a release. for full site editing and agrees to own the ticket.

Props @jorbin, @chanthaboune, @Clorith, @youknowriad, and @davidbaumwald for discussing the above plan and reviewing before being published.