Search engines can provide any information you want quickly. However, do you know what makes that possible? It is a web crawler.
This web crawler is responsible for making search engines work properly and correctly. Many people do not know its existence, but its function cannot be underestimated.
Therefore, in this article, we will discuss web crawlers in depth. Because not only is he responsible for finding information, but he also has many benefits, you know. Listen to the end!
Web Crawler Definition
The definition of web crawlers – or often also called spiders – is a tools for indexing and downloading content from the internet, then storing it in a search engine database.
So that when someone is looking for information, the search engine will immediately display relevant results from the database.
If you still need clarification, try to imagine a librarian. The librarian is in charge of tidying up the books in the library so that visitors can easily find the book they are looking for.
These books are organized by category and topic of discussion. Thus, librarians should look at the title and brief description of the book first before placing it on the right shelf.
Web crawlers collect/index any information that is useful on the internet. From article content, images, videos, and sounds to email addresses and RSS feeds.
Web Crawler Example
Every search engine on the Internet has its own web crawler. Therefore, if you do a search with the same keyword on another search engine, it will produce different results.
Some other web crawlers besides Googlebot are as follows:
- Bingbot from Bing
- Slurp Bot from Yahoo
- DuckDuckBot from DuckDuckGO
- Baiduspider from Baidu (a search engine from China)
- Yandex Bot from Yandex (a search engine from Russia)
- Sogou Spider from Sogou (a search engine from China)
- Exabot from Exalead
- Amazon’s Alexa Crawler
As the ruler of the search engine market share, Google displays much better search results than other search engines. Therefore, you must make it a priority for your website to be indexed by Googlebot.
For more details let’s have a look at explanation below:
There are various choices of web crawlers that you can use. Some of them are free, but some are paid.
Some examples of popular tools for web crawling are as follows.
1. Google bots
Googlebot is the most widely used web crawler today. As the name suggests, this web crawler belongs to Google. Googlebot collects various documents on a website to create an index that can be searched by the search engine.
This one web crawler refers to two types of web crawlers, namely desktop crawlers and mobile crawlers.
2. HTTrack
HTTrack is an open-source web crawler. You can download world wide web (www) sites from the internet onto your computer so you can view them offline.
If you have downloaded the site’s content, you can open it through your browser without an internet connection.
3. Cyotek Web copy
Similar to HTTrack, Cyotek Web copy can be used to download websites from the internet to your computer.
One of the advantages of this web crawler is that it allows users to choose the part they want to download. So, you can choose if you wish to download all aspects of the site, certain photos, and so on.
4. Webhoses
The next example of a web crawler is Webhose. Webhose is a web crawler that can turn unstructured website content into machine-readable data feeds. The data feeds can include many data sources, such as online discussions, news sites, and more.
How Do Crawlers Work?
The internet is always changing and developing all the time. Because it is impossible to know the exact number of pages on the internet. This web crawler starts its work based on a list of page links that it already knows from the sitemap of a website.
Now, from the list of sitemap links, he will find other links scattered in it. After that, it will crawl the links it just saw. This process will be repeated in the next link and can continue without stopping.
However, this web crawler does more than a crawl. There are several rules that they still have to obey, so they can be more selective in crawling. Usually, in crawling, he considers three things:
1. How Important and Relevant a Page is
Web crawlers only sometimes index everything on the internet. It determines which pages need crawling based on the number of other pages linked to that page and the number of visitors.
If a page appears on many other runners and gets a lot of visitors, chances are that page is really important.
This important page usually contains content or information many people need, so search engines will definitely include it in the index so people can access it more easily.
2. Routine Visits
The content on the internet is always changing every second. Either because of an update, deleted, or moved to another place. Therefore, web crawlers need to visit various website pages regularly to ensure the latest version of the page is in the index.
Moreover, suppose the page is important, and there are many visitors. In that case, certainly, he will often make regular repeat visits there.
3. Obey Robots.txt
The web crawler also determines which pages to crawl based on what robots.txt wants. So before crawling to a website, it will check robots.txt from that website first.
Robots.txt is a website file containing information about which pages may be indexed and which pages may not.
Web Crawler Functions
The main function of web crawlers is indexing content on the internet. But besides that, several other functions are equally important:
1. Comparing Prices
Web crawlers can compare the prices of a product on the internet. So that the price or data of these products can be accurate. So, when looking for a product, the product price will appear immediately without entering the seller’s website.
2. Data for Analysis Tools
Website analysis tools such as Google Search Console and Screaming Frog SEO rely on web crawlers to collect data and perform the indexing. So that the data generated is always accurate and up to date.
3. Data For Statistics
Web crawlers also provide important data that can be used for news websites or statistical websites. For example, search results will appear in the News section if you follow the Google News listing method. For this reason, websites need a special sitemap which will be crawled by web crawlers later.
What effect do web crawlers have on SEO?
A web crawler is a tool that functions to do crawling and indexing. So, if IAR doesn’t index your website, then your website won’t appear in search results. If the website appears in the search results, it’s possible to get the top position in the search results.
So, before you do any SEO tactic, make sure your website is indexed first.