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Google Chrome Pre-fetching

Google Chrome Browser can anticipate the pages that you might visit next and prepare those pages to load faster. How does it do it? DNS Prefetching.

One of the most frequently mentioned benefits of Google Chrome is the ability of the browser to load web pages at lightning speed. You usually don’t have to wait for a page to load; just click a link, and the page is there. The speed with which pages are delivered to you in Chrome is made possible by a feature called DNS pre-fetching. It’s how Chrome prepares pages to load quickly. When you go to a web site using a normal browser, the browser must “resolve” the domain (web address) that you seek; it translates the .com address into an IP address, such as 192.124.1.1. This process can take time, ranging from milliseconds to several seconds (in case of a timeout). Chrome, unlike other browsers, anticipates your next move. While that sounds mystical, the truth is that this feature is most effective when you contact a web site through a page in the web browser and not by manually entering a web address. When you open a web page in Chrome, the DNS pre-fetching feature scans the contents of your page for hyperlinks pointing to another web site. In anticipation of your next move, Chrome resolves these DNS address while you are on the web page, but before you click a hyperlink. This prevents you from having to wait once you click the hyperlink; the page loads almost instantly, and the amount of time that saves over the course of a day can be significant. If you have any doubts about the efficiency of this feature, just type “about:dns” in the address bar in Chrome, and you’ll see a full display of time saved using this feature.

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