Two main types of cache headers, cache-control and expires, define the caching characteristics for your resources. It's also important to remember that what we think of as browser caching may in fact take place at any intermediate stop between the original server and the client-side browser, such as a proxy cache or a content delivery network (CDN) cache. It's beneficial to you and your users to determine which types of content are more static and which are more dynamic. Your site's logo image, for example, might almost never change, but your site's scripts might change every few days. Enabling Caching #Ĭaching works by categorizing certain page resources in terms of how frequently or infrequently they change. Maximizing cache usage is critical to speeding up return visits. Still, a significant number of your users may revisit your site with at least some of its components already cached, and that can make a huge difference in load time. Even repeat visitors may not have much in the HTTP cache they might have manually cleared it, or set their browser to do so automatically, or forced a fresh page load with a control-key combination. Of course, every first-time visitor to your page arrives with nothing yet cached for that page. You can read about how these caches vary in this excellent article, A Tale of Four Caches. While HTTP caching is standardized per the Internet Engineering Task Force (IETF) specifications, browsers may have multiple caches that differ in how they acquire, store, and retain content.
PRIVATE CACHE WINDOWS DOWNLOAD
The next time the browser hits that page, it can look in the cache for resources that were previously fetched and retrieve them from disk, often faster than it can download them from the network. The first time a browser loads a web page, it stores the page resources in the HTTP Cache. You can give the browser choices about where it can retrieve a resource from, and that can make a big difference in your page's load speed. All the text, images, CSS styles, scripts, media files, and so on must be retrieved by the browser for display or execution. When someone visits a website, everything the site needs to display and operate has to come from somewhere.