Customizer – See a preview in real time.

Inc. Theme Customization screen allows site admins to tweak a theme settings and see a preview of those changes in real time. This Theme Customizer, allows user to customize and add controls to the “Appearance” → “Customize” admin screen. The Theme Customization screen (i.e. “Theme Customizer”) allows site admins to tweak a theme’s settings, or widgets, and see a preview of those changes in real time.