What Is Crawler? How Does A Crawler Work?

What Is Crawler? How Does A Crawler Work

A tracker is a computer program that automatically tracks documents on the web. Trackers are primarily programmed to perform repetitive actions to automate browsing. Search engines often use crawlers to navigate the Internet and build an index. Other trackers look for different types of information, such as B. RSS feeds and email addresses. Synonyms are also “bot” or “spider”. The best-known web crawler is the Googlebot.

How Does A Tracker Work?

In principle, a tracker is like a librarian. It searches the web for information that it assigns to specific categories and then indexes and catalogues it to retrieve and interpret the data it tracks.

The operations of these computer programs must configure before starting a scan. Therefore, each order defined in advance. The crawler then executes these instructions automatically. The crawler results used to create an index that the output software can access.

The information a tracker collects from the web depends on the instructions.

This graphic shows the links displayed by a crawler:

Web Crawler

Web crawlers, also identified as web spiders or Net bots, are plans that automatically browse the Internet to index content. Crawlers can see all kinds of data like content, links on a page, broken links, sitemaps, and HTML code validation.

Search appliances such as Google, Bing, and Yahoo use crawlers to correctly index took pages so that users can find them quicker and more professionally when searching. Without web crawlers, there is nothing to tell you that your website has new and updated content. Sitemaps can play a role here too. So for the most part, web crawlers are a good thing. However, sometimes there are also scheduling and loading issues, as a crawler may be constantly voting your site. This file can help regulator trace traffic and ensure that your server is not overloaded.


The typical goal of a crawler is to make an index. The crawlers are, therefore, the basis of the work of search engines. The first search for content on the web and then make the results available to users. For example, specific crawlers point to current websites relevant to content when indexing.

Web Crawlers Also Used For Other Resolutions

Value comparison portals search the Internet for information on specific products to accurately compare prices or dates.

In the area of ​​data removal, a crawler can collect email or postal addresses of publicly available companies.

Web analytics tools use trackers or spiders to collect incoming or outgoing visits or links on the page.

Trackers are used to supplying data to information centers, e.g. Ex.  B. News pages.

Examples of a crawler

The most famous crawler is the Googlebot, and there are many additional examples as search engines often use their web crawlers. For example


  • Bingbot
  • Slurp Bot
  • DuckDuckBot
  • Baiduspider
  • Yandex Bot
  • Sogou spider
  • Exabot
  • Alexa Tracker [1]

Tracker Versus Scraper

Unlike a scraper, a tracker only collects and prepares data. However, scraping is a black hat technique that aims to copy data in the form of content from other websites to place it on the website itself in this way or a slightly modified form. While a crawler mainly processes metadata that is not visible to the user at first glance, a crawler extracts certain content.

Block A Tracker

If you don’t want sure crawlers to crawl your website, you can exclude your user agent using robots.txt. However, this cannot prevent search engines from indexing your content. The no index meta tag or the official tag serve this purpose better.

Importance For Search Engine Optimization

Web crawlers like Googlebot reach their purpose of evaluating websites in SERPs by crawling and indexing. You follow permanent links on the WWW and websites. Each tracker has a limited time frame and budget per website. Website owners can use Googlebot to track the budget more effectively by optimizing website structure such as navigation. URLs that are considered more important because of many sessions and reliable inbound links generally crawled more frequently. There are specific measures to control crawlers, e.g. B. For example, Googlebot, e.g. For example, the robots.txt file, can contain specific instructions for not crawling certain areas of a website and the XML sitemap.

AlsoRead: What is the Meta Tags and Why are They Important

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