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Crawlers – how do they work?

A properly functioning website is the basic element of marketing in the 21st century. Every entrepreneur wants to display as many internet users as possible in organic search results. However, it is worth remembering that optimizing a website for SEO also means ensuring a transparent and friendly appearance not only for users, but also for Google robots that regularly verify its content. In today’s post, we’ll show you how crawlers work, what they are and what you should know about them. Let’s get started!

Web crawler – what is it?

The term web crawler is a little-known name for the majority of Internet users who do not specialize in SEO or web development activities on a daily basis. At Paraphrase Online, however, we believe that, irrespective of the industry, it is worth getting acquainted with this issue and knowing what it means exactly.

A web crawler (the so-called internet robot) comprehensively checks various elements on your website. It examines the “inside” of your website and draws conclusions, which it then uses to increase or decrease its position in organic search results, or SERPs. It is usually the content and in-depth structure of a given website.

It is also worth mentioning that website crawlers are primarily used by SEO agencies to index their clients’ websites. Thanks to this, the implementation of a positioning strategy may turn out to be effective after several days from the start of cooperation between contractors.

How do web crawlers work?

Web crawlers collect meticulous information about domains in order to index them correctly and regularly monitor changes. Googlebots examine the “inside” of a domain based on three main types of scans – deep crawl, fresh crawl and main crawl. The first one is an in-depth study of the site, the second is the verification of pages that are frequently updated (we use it most often), and the third (main crawl) has a similar task to deep crawl, with the difference that it concerns only the bookmarks that are priority from the point of view of users ( eg “about me” or “contact”). We explain the details below!

Google crawlers – what are the types of scans?

As we mentioned before – there are 3 types of scans performed by the robots of the Mont Blanc giant. Their full names are Google’s deep crawl, Google’s fresh crawl, and Google’s main crawl. We present the importance of all types of scans!

A. Google’s deep crawl
Google’s deep crawl is one of the most accurate types of scans offered by the Mont Blanc giant. It examines the “interior of the website” comprehensively, taking into account internal linking, dofollow links, HTML and CSS code, as well as other priority elements, according to Google’s creators (e.g. implemented functionalities). It even occurs several times a month – it depends on the frequency of making changes to a particular site.

B. Google’s fresh crawl
Google’s fresh crawl is responsible for updating the most important parts of the page that users see. This allows them to be up to date with all the news added by the visited domain. This type of scan is performed at least once a day.

C. Google’s main crawl
Google’s main crawl is a type of scan that is performed approximately once a week. It scans about “about me” tabs and contact pages so potential customers can regularly find out key information about your domain.

What are the functions of crawlers on the Internet and what elements do they take into account during indexation? – practically about web crawlers in 2022!

Now that we’ve found out what it is, how crawlers work and what their types are, it is worth paying attention to another priority aspect – crawler functions.

Well, the main task of Googlebots is to visit websites, thoroughly verify the content, and then send key data to a special index (i.e. the database on the basis of which the algorithms arrange the search order). As a consequence, getting traffic to our site from the search engine is possible due to the indexation of the site by indexing spiders.

When indexing, Google robots take into account 3 main elements of the domain, on the basis of which they evaluate specific websites – content, meta tags and alt descriptions in graphics.


One of the most important elements of any website. The value of your domain in the eyes of Googlebots depends on the quality and correctness of the posted content. Web crawlers verify the subject matter and categorize websites based on the content. Therefore, we recommend that you take care not only of grammatical or spelling correctness, but also moderate saturation with keywords, its clarity and originality.

Meta tags

When it comes to meta tags in terms of positioning and web crawlers, the title tag is the most important. He is responsible for SEO and, consequently, the correct indexation of the website. It should contain a keyword and content that will convince the internet user to enter the website (or interest him).

When it comes to tag description – crawling robots do not take it into account. However, the meta description should be developed with attention to Call To Action (CTA) and other elements that will increase the likelihood of a potential buyer visiting the website.

Alt descriptions in graphics

Alt descriptions in graphics are a must. Web crawlers do not see pictures, and thus – when indexing, they take into account alternative descriptions of graphics or photos.

Popular SEO crawlers – what does it look like in practice?

In practice, popular crawlers perceive the completely raw form of your domain in the form of source code, CSS, website content and key phrases placed in the appropriate parts of the text. When building a website for SEO, we recommend focusing primarily on content, because it is the content that determines the position in search engines.

As an experienced SEO agency, we put content first, but when working with our clients, we perform regular website audits to identify defects, the repair of which will result in an increase in the position in SERPs. As a consequence, we also present omissions in the source code and CSS to make the next work of Googlebots run more efficiently.


Crawlers (also known as robots, spiders, crawlers or bots) are programs used by search engines to verify the code, structure and content of websites available in search engines. Their qualitative assessment selects domains in SERPs – those that are the most valuable occupy the highest positions in Google.


Below are the answers to the most frequently asked questions about web crawlers.

What are web crawlers doing?
Web crawlers check http status of subpages, verify duplicate content and number of headers, count characters in content and control other priority metrics of your website.

Are Google algorithms the same as Googlebots (web crawlers)?
Not. Google algorithms are a sequence of defined activities necessary to achieve high positions in organic search results. Googlebots, on the other hand, are programs that collect the most important data about the structure, pages and content on the Internet, which regularly select domains in the context of places in organic search results.

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