Understanding search engines is a key part of the puzzle when trying to optimize your website to rank higher. This chapter will break down how search engines work, specifically focusing on Google. Examples of other search engines include Bing, Yahoo, Baidu, Yandex, plus many more. Despite the fact that there are a lot of search engines in existence, Google is the most popular and a large percentage of searches occur on it every second of every day.

How do search engines work?

Search engines look at billions of web pages and evaluate the content based on factors such as authority and relevancy. After crawling all the content available, the search engine will index the pages and rank them based on certain criteria. Google, Bing, and others catalog anything from images to videos to web pages and PDF files. The websites will then appear in the SERPs or search engine results pages in order of relevance.

To put it simply, search engines have three main functions. They crawl, index, and rank.

What is crawling?

Search engines crawl the Internet for new or updated content all the time. Content can be anything, not just a web page but images or even PDFs. PDF stands for portable document format, and it is a file format that a computer software company called Adobe developed in 1993.

Popular and well-known websites that receive a lot of traffic are crawled more often than lesser-known sites. 

Google will search the web by following internal and external links as well as reading sitemaps. A sitemap lists all the URLs of a website and provides information about the links. Since search engines find new pages from links, link building will boost your ranking. Building links refers to increasing the amount and quality of links to your website.

Crawl accessibility refers to the ease in which search engines can access and catalog content on a website. If your site doesn’t seem to be appearing on SERPs, then it is possible there are some underlying crawlability issues. 

Here are some reasons that may explain why your site isn’t appearing on search engines:

  • When you make a new site, it takes some time for the search engine to crawl the content. As such, give the bots some time to find your recently created website and index it.
  • Without any links to your website from other sites, search engine bots will have a tougher time finding your content. In this scenario, make an effort to build links by reaching out to others, leveraging social media, and other strategies.
  • Easy navigation of your site is crucial not only for human users but also for search engines. Ensure your website is designed in a way that lets search engines crawl your content without any issues. Some methods to improve navigation include using accurate titles, adding ALT text to images, linking to other internal pages, etc.

Another thing to consider is the crawl budget or the average number of pages that Google will crawl on your site at a given time before the bot leaves. You can tell the search engine to ignore certain pages you don’t care about, especially if you have a website with a lot of pages. That way, you optimize for the crawl budget and ensure the bot only crawls important pages.

More often than not, you want the content on your website to be visible to search engines, so Google can crawl your site. However, sometimes you don’t want bots to index certain pages. You can block search engines from crawling and indexing them. For instance, if you have old pages with little or duplicate content, you may want to stop search engines from finding them. In this case, you can use robots.txt to direct the bot accordingly.

Robots.txt, which is also called robot exclusion standard or robot exclusion protocol, is a file that communicates with search engines about what to crawl and what pages to avoid crawling. For sites that do not have a robots.txt file, the bot will crawl the site. For sites that have the robots exclusion standard, the search engine will typically crawl the site according to what is outlined in the file.

Another thing to consider is any private or personal content you don’t want to be shown to the public such as administrative pages. That being said, if you place the URLs of these pages in your robots.txt file, people can find them and see information you may not want visible to others. As a consequence, many websites will block search engines from indexing certain pages with the “noindex” meta tag in the HTML (hypertext markup language) code.

It goes without saying that you want the search engine bot to crawl all your important content. Don’t hide content behind protected pages that require users to log in to access them. This is because the Google bot won’t be able to log in and crawl the content. Make it easy for search engines to find pages on your site by linking to them. When possible, use HTML over JavaScript since Google is better at reading the former.

Create a sitemap, which is a list of URLs on your website to help the bot find and crawl your content. Like a map, it gives the search engine a guide to your site. Include the pages you want crawlers to index, and submit the sitemap through Google Search Console. This web service provides information regarding your website such as how much traffic you are receiving. You can use the tool to fix and troubleshoot common issues. In Google Search Console, you can find a report with crawl errors to see if the bot is encountering any problems when crawling your website.