CKEditor 5 will attempt to enable plugins that provide equivalent toolbar items to those used prior to switching to CKEditor 5. All core CKEditor 4 plugins and many popular contrib plugins already have CKEditor 5 equivalents. In some cases, functionality that required contrib modules is now built into CKEditor 5. In instances where a plugin does not have an equivalent, no data loss will occur but elements previously provided via the plugin may need to be added manually as HTML via source editing.