How Search Engines Index & Crawl Websites

We have read a lot about optimizing the websites and following the SEO techniques to rank higher on Google Search Results page. We usually find two kinds of results on any search engine’s result page. One is the paid search results which are sponsored by the search engines in exchange for monetary benefits and the second is the organic results which are ranked by the algorithms followed by every search engine. Every search engine has its own algorithms and policies to rank websites but the way they index and crawl websites are almost the same. 

If you have a curiosity to understand how this worldwide web overloaded with tons of content never fails to give you the best and the most relevant results every time, it is time to dive into the article and has a quick look at how search engines index and crawl all the websites. 

Everything begins with crawling, this process is used by the search engines to find new content across the web. It can be a new website, a new page, any updates to the existing content or dead links. Each search engine has a program that is usually called a crawler or a bot. It is an algorithm that helps determine when and which sites need to be crawled. It uses different parameters to even calculate how often a website should be crawled. This means a news website that is popular and posts content regularly will be crawled more often than a website of a local shopping store. Factors like SEO efforts, website optimization, relevant content, etc help the search engine prioritize websites. As the crawlers move across the website, it keeps a record of any new links it finds on the existing pages. These pages are later crawled and new content is found.

The next process is indexing. As soon as all the pages stored by crawlers are crawled, the search engine then processes every word on each page to compile an index with its location. This information is organized using the algorithms and is sorted as per its importance. Now when a user looks up for a word online, the search engine returns relevant results within a fraction of a second. Therefore every search engine needs a lot of space to store such detailed information. Google and Microsoft thus have millions of servers for this very reason.