Please note that Gutenberg is under rapid development and is intended for testing purposes. We cannot provide support for every feature of Gutenberg until it’s official release in WordPress 5.0.
To get started, install and activate the
The Gutenberg menu item will now be visible. Clicking this link will take you to the Gutenberg editor filled with demo content which you can use to test out the editor.
Add New Post will now bring up the Gutenberg editor instead of the classic editor:
To switch back to the classic editor, navigate to
Posts → All Posts, hover over the post you wish to edit and click the Classic Editor link:
More information about the Gutenberg plugin can be found here