Searching for information on the web makes you wonder about a few things. Like, how are all the answers at our fingertips? It is almost unbelievable that all we need to do is type in a question into a search engine and receive a list of answers.
Search engines are essentially gateways to information. However, their sidekicks play a major role in gathering information from online content. These sidekicks are web crawlers. Not only do they help gather the information you seek, but they are a crucial part of your SEO (Search engine optimization) strategy.
Now, you may be asking, “What is a web crawler?”. Below we will answer that question, and more, so keep reading to learn about how web crawlers work and what they are exactly.
Definition of Web Crawler
There are many names that identify web crawlers; Spiders, Bots, and Robots being the common ones. These names are quite descriptive, and they sum up their role fairly clearly. They travel across the internet to index the pages presented by search engine results.
Search engines aren’t all-knowing, and they can’t magically make information appear without web crawlers. These crawlers need to scour the internet, indexing information before it can be delivered to the correct place. Crawlers rely on key phrases and words (Keywords).
It is kind of like browsing a new store. You have to explore all the isles before you can grab what you need. It is the same way with search engines and spiders. They need to crawl through the internet before the information is gathered and presented.
This analogy also examples how crawlers will travel in between page links. When you are in the store, you can’t see what’s stocked behind the box of hamburger helper before you move it. With crawlers, they have to have that starting point too, usually a link, before they are able to find the next link and next page.
How Do Web Crawlers Work?
Basically, search engines will visit (crawl) through sites using links that connect them as doorways. That being said, if you have a new website that doesn’t contain any links that connect other pages to yours, you need to ask the search engine to crawl through your site via submission of your URL to Google Search Console. To put it simply, crawlers are explorers traveling from land to land.
They are constantly looking for new links on pages, storing them in their map, and providing the information when relevant. There is a kicker, a website crawler is only able to travel through public pages. If the private page can’t be crawled through, it gains the daunting label of “Dark Web.”
While on the page, web crawlers gather the information found on it, such as; Meta tags, copy, other content. Then, once they have collected all the needed information, they store it in an index. The index is then referred to by Google’s (or whatever search engine you are using) algorithm. It is sorted by their words and later referred to rank a site for users.
Web Crawler Examples
Popular search engines, all of them, use web crawlers. The larger search engines will actually utilize multiple crawlers for different purposes. For example, Google uses Googlebot as its main crawler. Googlebot encompasses desktop and mobile crawling. However, there are additional bots that Google uses; Googlebot Images, Googlebot News, AdsBot, and Googlebot Videos.
Here are some other web crawlers that popular browsers use:
- Yahoo! Slurp
- Baiduspider
- Yandex Bot
- DuckDuckBot
Even Bing has its own standard crawler named Bingbot. Bing also uses several other bots to gather more focused information for refined searches. Fun fact, Bing use to primarily use MSNBot. However, it has begun to sit in the backseat for basic crawling and now has only minor crawling duties it needs to deal with.
Web Crawlers & SEO
We stated before that web crawlers are important to SEO. But “How?” you may ask. SEO is needed for improved rankings on search engines. It is required so pages can become reachable and observed by an audience. Well, it has to be readable and reachable for web crawlers as well. In fact, the first process of locking onto a page for results to a search is to have crawlers travel through the page first. They do this regularly, so when you make changes, they stay updated, and your ranking improves based on content and keywords.
It is important to know that crawling goes way beyond the start of an SEO campaign. The behavior of web crawlers is a proactive measure for helping websites, and web pages appear in search rankings and results. They basically enhance the experience of the user. There is more information below about the relationship between SEO and web crawlers.
Managing Crawl Budget
Your pages that are newly published have a chance to appear in the SERPs (search engine results pages) because of ongoing web crawling. That being said, you aren’t going to see unlimited crawling from any search engine. In fact, they have a budget that guides the bots. This crawl budget guides the bots in:
- Acceptable Server Pressure
- Choosing pages to scan
- How Frequently to Crawl
While a crawl budget sounds like a limitation, it is actually helpful to your site. If there was unending activity by web crawlers on your site, it would overload. You are able to adjust the crawling through the rate limit and demand. This will keep your site running as smoothly as possible.
The crawl rate limit will monitor the fetching process from sites, so the load speed doesn’t take a hit. You can alter the crawl rate on Google Search Console if it is Googlebot causing issues or errors.
The crawl demand, however, is basically the interest level that users (and Google) have on your site. That means, if your following isn’t large yet, Googlebot won’t be crawling very often. Popular sites do see an increase in crawling.
Web Crawler Roadblocks
You can purposefully block web crawlers from coming to your website or pages. Truth be told, not every page of each website should rank in the SERPs. Roadblocks will help protect irrelevant, sensitive, or redundant pages from being scanned for keywords.
One of the roadblocks is the index meta tag. This will stop search engines from ranking and indexing specific pages. Admin pages, internal search results, and thank you pages are often adorned with a no-index tag.
