Web crawler or web scraper might be weird terms to say out loud, but there's no denying how important they are to understand if you want to take advantage of search engine optimization in the digital age and drive traffic to your website.
Most people understand the basics of web crawlers: they're automated processes that read through your webpage content and categorize your website. But knowing their purpose is much less important than knowing how they achieve those conclusions. Today, we'll explore how web crawlers help users find the pages they need and how you can ensure the right people find your website.
Web Crawlers in Review
Before we dive into how web crawlers work, let's look at their functionality or why they're helpful. Search engines use web crawlers to explore the bounds of the internet, adding new websites to their repertoire of results and categorizing those websites according to various factors like keywords.
Googlebot, Bingbot, Baiduspider, and other spider bots are not actually robots physically combing through the world wide web's billions of websites; they're part of a program that sifts through webpages, their HTML code, and their domains. Then, they rank their findings according to the parameters set by the search engines.
How Do Web Crawlers Work
The first step to web crawling is to find your website. Your website must be reachable by web crawlers, and it must be found easily. Web crawlers can find your website by following links from other websites it has already crawled, or you can submit a sitemap that details your site's architecture and ask the search engine to crawl your website specifically. The easier your website is to navigate, the more likely it is to be crawled by multiple search engines.
Once a web crawler begins the process of web scraping, it will list all of the URLs and links within each page of your website. It will later check those URLs to ensure that your links work correctly and lead searchers to real websites.
As they explore, web crawlers add URLs to their indexes so that those pages can appear when someone searches for them in the search engine. And it isn't just text that web crawlers catalog either. It's pictures, videos, downloadable files, and .gifs too. Web crawlers will determine what websites are about by analyzing keywords, links, and how recently it was updated.
Keep in mind that web crawling is far from a perfect science. Part of the reason why so many websites submit sitemaps is to clarify when they should appear in search results and to prevent any misunderstandings via web crawler identification.
Factors Related to Crawling
Once a website has been categorized and scoured for keywords, website crawlers perform various searches inside a website to check how it ranks based on numerous other factors. A web page's 'relevance' will then dictate how highly it is shown when someone searches for relevant keywords related to that website.
This ranking also determines how much time the web crawlers spend crawling your website. If they move through a few pages and determine that you're presenting low-quality content, they won't continue to crawl through your website, even if they haven't hit your valuable content yet.
Conversely, if your pages load quickly and they rank your content as high value, they'll spend more time exploring your content and will visit your website frequently in the future to check for updates.
In the sections below, we look at the other factors that affect a website's rank according to web crawlers. It's important to note that major websites like Google only release basic information related to their web crawling and keep a significant part of their algorithm a secret.
No one wants to wait forever for a website to load, and that same thing goes for web crawlers. They have tons of information to sift through and don't have the time to wait for a page to take multiple seconds to load.
Rankings often take load time into account, so it's important to frequently revisit your website's loading time to ensure that customers and web crawlers don't encounter any SEO issues.
There are ways to block search engine crawlers from crawling your website, and, in most cases, these are accidental and not something most website creators want. If during the crawling process, your website is accidentally listed as non-existent, contains too many broken links, or expressly prohibits web crawlers from entering your site, your website will not be listed as a result in search engines.
The robots.txt file, or the robot exclusion protocol, explicitly designates certain pages from your website to be crawled. You can use it to keep your entire website off-limits, but most people use it to show which pages they want to be indexed and which ones to be skipped.
You want the web crawler to spend its time crawling your most valuable pages without wasting time on pages that aren't as important.
Web crawlers are partially present to ensure that users enjoy their experience on the resulting web pages from their search. Search engines perform better when people feel like their questions are answered, and the links are good. That's why web crawlers check the status of your linked URLs. When you have lots of broken links, they won't score your website as well.
Part of this factor is outside of your control, but it's something to consider if you have affiliates or partners online. When more websites link to your website, it not only gives web crawlers more opportunities to crawl your website and increases your ranking.
Having several external links to your website indicates a high demand for your content which Google and other search engines acknowledge by featuring your website further up their results pages.
It isn't just about the quantity, though; search engines also look at link quality. Link quality checks how reliable the source linking to your website is, how many other links are on that page, where the link is, anchor text, and how relevant the linked page is to the starting website.
Links to similar content located in the text of a blog post using words that accurately describe the link are valued more than links at the bottom of a page that lead to websites only tangentially related.
Artificial intelligence and machine learning have come a long way toward determining implied user intent through search engines. Web crawlers categorize and rank content based on the query and implied user intent of a specific search. For example, if someone searches for seeds to plant in spring, they're likely looking to buy those seeds, not just learn more about them.
Generally, search engines prefer to list newer content first. While they do take page updates into account, your website is more likely to rank higher among web crawlers if you routinely post new content. The freshness of your content can't take the place of your content's value, though. Search engines weigh each factor differently, and freshness tends not to have a ton of weight, but it is a significant thing to consider.
Despite their large numbers, web crawlers can't be everywhere at once. They were never designed to crawl through every website simultaneously, taking updates and deletions into consideration. Web crawlers prioritize websites with high traffic and lots of interest from searches.
This may seem recursive since websites need to be crawled to increase their traffic, and web crawlers prefer websites that already have a lot of traffic, but you can also request web crawlers to crawl your website so you can break into the cycle.
Obviously, copying the content from other websites is an issue, but this also refers to using the same content multiple times on your own website. This doesn't mean that you can't put your slogan or identifying message on multiple pages, just that you can't re-use multi-paragraph descriptions over and over again without getting penalized in the rankings.
Web crawling might sound complicated, but it's a rigorous searching and indexing process that enables search engines to provide relevant content to their customers. Web crawlers work by evaluating your website based on several factors to determine what it's about and how high it should rank compared to other similar websites.