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What is a crawler?

Crawlers are like explorers on an expedition in a foreign land. A crawler sometimes referred to as a “bot” or “spider,” is a computer program that search engines employ to automatically explore web pages and links to gather information for indexing. When a crawler accesses a website, it collects all the text, external, and internal links and stores them in a database. The saved links are eventually ranked and shown to users by Google’s algorithm according to the searched terms.

Crawler examples

Googlebot is one of the most well-known and widely used crawlers. As most search engines use their versions of web crawlers, there are multiple examples available:

  • Bingbot
  • Slurp Bot
  • DuckDuckBot
  • Baiduspider
  • Yandex Bot
  • Sogou Spider
  • Exabot
  • Alexa Crawler

How does a crawler function?

It is impossible to estimate the entire number of web pages on the Internet since it is always evolving and growing. A list of identified URLs serves as the web crawler’s “seed,” or initial point of entry. Links to other URLs on those pages are added to the list of pages to be crawled when they have finished crawling the web pages at those URLs.

The sheer amount of websites on the Internet that might be indexed for search makes this a never-ending process. A web crawler conforms to a set of rules that allow it to be more selective about which sites to scan, the order in which to crawl, and how frequently to crawl them again to look for content changes. Among the selection standards are:

  • Number of backlinks
  • Page views
  • High-quality, authoritative information/brand authority

In addition, crawlers need to keep an eye on:

Reviewing websites: Information on the Web is often updated, deleted, or relocated. To ensure that the most recent version of the material is indexed, web spiders will need to frequently review pages.

Robots.txt specifications: The robots.txt protocol is another factor used by web crawlers to choose which pages to crawl. Text files called robots.txt contain restrictions for how bots may access a hosted website or application. These guidelines specify which web pages and links the bots may crawl.

The unique algorithms that each search engine incorporates into its spider bots provide varied weights to each of these characteristics. Although the objective is the same—to download and index material from web pages—web crawlers from various search engines will perform significantly differently.

Uses of a crawler

A crawler’s basic objective is to build an index. Additional uses for crawlers include the following:

  • For reliable pricing or data comparison, price comparison portals scour the Internet for information on certain items.
  • A crawler can gather publicly accessible company email or postal addresses for data mining.
  • Crawlers or spiders are used by web analytic tools to gather information about page visits, inbound links, and outgoing connections.
  • Crawlers are used to supply news sites and other information centres with data.

Significance for search engine optimization

Web crawlers, as we currently understand, are in charge of reviewing and indexing online information for search engines to rank websites. As part of effective technical SEO, understanding web crawlers is just one aspect that can significantly increase the performance of your website. It is essential to crawl your website correctly to optimize it for search engines. Web crawlers are useful not just for diagnosing errors on your site, but also for the following benefits:

  1. Crawlers for your website operate in the background and won’t slow it down when in use. They won’t obstruct your routine activities or affect visitors to your website.
  2. The majority of crawlers contain built-in reporting and analytics tools that you can export into various forms, such as an excel spreadsheet. With the help of this function, you may swiftly explore the audit’s findings and save time.
  3. The ability to program web crawlers to automatically crawl your website is a terrific feature. By doing this, you may continuously monitor site performance without having to manually retrieve a crawl report each time.

A fantastic technique to make sure your site is healthy and ranking correctly is to conduct routine site audits using crawling tools.

Ways to increase your site crawl rate

The crawler’s frequent and consistent visits to your site are the first indication that Google finds it appealing. Therefore, creating a website that search engines consider significant and relevant is the most effective strategy to receive regular and in-depth crawls.

Keep in mind that you cannot compel Googlebot to visit you more frequently; all you can do is extend an invitation. The following actions might be taken to speed up the crawl rate:

  1. Upgrade and refresh content frequently – Try to contribute fresh, original content as frequently and consistently as you can for the best update rate.
  2. Evaluate your server – Evaluate your server’s uptime and Google Webmaster Tools reports of the pages that have not been reached to ensure proper operation. 
  3. Monitor load time – It’s important to remember that the crawl has a limited budget; it won’t have time to delve into your other pages if it has to crawl your large photos or PDFs for too long.
  4. Review links – It’s important to make sure the internal links on your web page aren’t duplicating content: remember, the more time the crawler spends figuring out your duplicate content, the less time it will spend on useful or unique pages on your site.
  5. Add more links – Try to obtain additional backlinks from frequently visited websites.
  6. Verify the meta and title tags – Make sure the title and meta tags for each of your pages are distinct.
  7. Test continuously – Track and test the Google crawl rate for your website to determine what is effective and not.
  8. Strive to increase social media shares – Despite Google’s claims to the contrary, social links may increase the frequency with which your site is crawled by Google.

Negative aspects of crawlers:

Crawlers can be used for the malicious purpose such as:

  1. Scraping data that is classified, private, or copyrighted.
  2. Scraping a website without the owner’s consent, disregarding its terms and services.
  3. A web server could crash under additional heavy load if data requests were made in an abusive manner.

Blocking a crawler

Your website can be protected with a robots.txt file to exclude certain crawlers from viewing it. That cannot stop material from being indexed by search engines, though. It is preferable to use the noindex meta or canonical tags for this.