Browser Caching

LiteSpeed Cache is a full-page cache. It takes expensive-to-generate dynamic content and stores it as easy-to-serve static files. While it handles dynamically-generated content well, it only handles dynamically-generated content. Static content such as images, video, or fonts is not included in any full-page cache. And yet, this content may be requested from the server repeatedly. Take, for instance, your site's logo. That image is likely to be displayed on every page that the user visits, which means the server has to repeatedly transfer that same image to that same user.

This is where browser caching comes in handy. With browser caching enabled, your logo (along with other static content) is stored locally on the user's device the first time it is requested. After that, the content is pulled from their local storage until the browser cache expires. Displaying a local image will always use fewer resources than transferring an image across the internet, no matter how fast your connection may be.

Normally, browser caching is enabled at the server level. However, if you do not have access to your server's admin, you can still enable browser caching through the LiteSpeed Cache for WordPress plugin's settings. You can choose to set this up at whichever level makes the most sense for your site(s). If either level is turned on, then browser caching will be enabled.

From the WordPress Dashboard, navigate to LiteSpeed Cache → Settings → Advanced and scroll down to Browser Cache.

Set Browser Cache to ON. That's it! Browser caching will now be enabled for your site. Most static files will be cached locally on the user's device, and will expire after one month.

If you are a server admin, you have somewhat more control. In the LiteSpeed Web Server Admin, navigate to Server > General and scroll down to Expires Settings.

Set Enable Expires to Yes.

Expires Default may be set to a number of seconds or left blank if you don't wish to provide a catch-all expiration.

Note: Be careful with this setting. It applies to all types of content, even HTML. This causes potential conflicts with LSCache, and can result in stale content being served to the user. If you are running LSCache, always leave Expires Default unset.

Set Expires by Type to a string similar to the example above, changing any file types or expiration times as desired. The example enables browser caching for all images, css, and javascript, and it sets all of their expirations to 604800 seconds (or one week). If you leave Expires Default blank (as you should, if you're using LSCache), then you must specifically include every file type you want cached by the browser in Expires by Type