WordPress is always adding amazing capabilities. Some WordPress features are well-documented and others aren’t so widely known — but they, too, can improve the usability and reach of your site. Here are six relatively unknown WordPress features that you’ll want to take advantage of!
Post thumbnails
Also known as featured images, post thumbnails are representative images that you can define for every page and post. With social sharing so critical nowadays, it’s essential that your theme supports post thumbnails; using a plugin like WordPress SEO by Yoast will equip your site with a preset microformat code that defines an image to display when people share your page. If you don’t have post thumbnails, you can update functions.php with one line of code:
add_theme_support( 'post-thumbnails' );
Child themes
There are some amazing themes available for purchase and download. Many of those themes are supported and provide updates as they fix bugs or add features. However, if you install a theme and customize it, you’re going to have to modify your code every time you upgrade the theme. A better option is to create a child theme. A child theme allows you to modify specific pages within your own theme but leave the parent theme alone so that it can be updated. Honestly, you should never be updating the core theme that someone else developed since there may be updates coming!
Mobile-responsive videos
If you’ve ever opened your site in a mobile browser, you might have noticed that your videos are cut off and don’t fit the width of the page. Install and activate the Jetpack plugin and add the following code in your theme’s functions.php file:
add_theme_support( 'jetpack-responsive-videos' );
Custom image sizes
If you find yourself resizing images in every post, you might need to modify your media settings in Settings > Media. This is where you can set the sizes to match your theme so that, each time you upload an image, it’s resized automatically to the sizes you defined. And if you wish to even add more sizes, you can add names and sizes in your functions.php file in your theme:
if ( function_exists( 'add_image_size' ) ) {
add_image_size( 'xwide', 600, 300 );
add_image_size( 'bigtile', 260, 260 );
add_image_size( 'smalltile', 90, 90 );
}
Excerpt length
Sometimes the default length of the excerpts on your blog’s page and category pages is too short to have an impact. As with virtually everything in WordPress, you can override that excerpt length by defining the number of words in your theme’s functions.php file. Here’s an example:
function new_excerpt_length( $length ) { return 65; }
add_filter( 'excerpt_length', ‘new_excerpt_length' );
Distraction-free Writing Mode
Menus and sidebars can be distracting as the clock is ticking and you’re looking to complete that next blog post. With the 4.1 version of WordPress, they’ve added a nifty little button on the top right of your editor that hides everything but the editor.

These WordPress features might have flown under your radar, but they’re definitely worth the time to get to know!