What is Web Crawling? How it works & Examples

The term ‘ crawling ‘ or ‘ crawler ‘ refers to the method or procedure used by Google search engines to classify and index every one of the existing web pages on the network.

This indexing is essential for the visibility and organic positioning (search engine optimization) of our page since it is what will determine what place it will occupy on the results page after user searches.

Suppose you already know the concept of ‘crawling’ or ‘crawler’ and want to learn more about SEO. In that case, we recommend reading the guides The secrets of SEO and How to apply SEO to your online marketing strategy.

Why is it called ‘crawling’ or ‘crawler’?

Now that you know what crawling or crawler is, you may be curious about the word’s origin from an etymological point of view. The method used by Google and other search engines to assign a position to our page after user searches (that is, its level of organic positioning or SEO) comes from the word ‘crawler,’ which is one of the several ways used to name to search robots, such as spiders or climbers.

What are crawlers? 

Crawlers are small programs that travel through the network, sent by Google (other search engines use similar tools) with a very clear roadmap:

1. Find all existing web pages.
2. Analyze them based on a formula or algorithm.
3. Assign each of them a certain position in the SERP.

We speak of search engine crawlers in the plural and not in the singular because there are different types of crawlers. Each of them is responsible for analyzing and scoring different information. One of them is the crawl budget, which assigns a specific time to each link. We have already analyzed a previous post in our marketing dictionary in detail.

Crawling parameters: Google’s great secret

Contrary to what alleged SEO search engine optimization gurus and articles published by Google itself might say, such as this one entitled How Search Works, where some general issues are explained (in a very attractive and visual way) about Google’s criteria for positioning the pages after user searches, the exact formula of the algorithm is not known.

It is known that there are more than 200 variables, among which are:

• The value of the contents, in quality and updates.
• The accessibility and fluidity in the navigation of the page.
• The structure of the page.
• The ease of access to the web by crawlers.
• The technical quality of the page, for example, its loading speed or the level of optimization for all types of devices, especially mobile phones (smartphones and tablets).
• The absence of errors.

At the same time that the aspects most valued by Google in each update of its algorithm are public knowledge, it is also known that others have lost strength, such as the direct inclusion of keywords in HTML headers (metatags).

The knowledge and study of these parameters to be considered in SEO mean that the concept of crawling is far from being completely abstract and incomprehensible. But its exact formula, that is, the specific weighting of each of the variables taken into account by the robots, remains Google’s great secret, jealously guarded by those responsible for possibly the most important company in the world in the field of Internet.

It is important to underline that crawling is the method to determine the order of the page after the search results are constantly growing, perfecting, and adapting to new technologies and ways of using the Internet. These are increasingly opting for navigation on mobile devices, voice searches, and the importance of the user’s location when searching for something on the web.