Web Crawler Architecture

Nowadays, companies of all sizes are heavily focusing on building strong online brands as the internet takes the leading role in how successful businesses get. Although this meant the creation of a website at first, online presence developed into something much bigger.

But, businesses today also have different tools and programs at their disposal which they can use for various purposes. Web crawlers are one of them, and they’re becoming increasingly popular.

What is a web crawler is a question we often see online, along with questions about how they work or how your business can benefit from the software. If you want the answers, make sure to keep reading!

What is web crawling

First things first, let’s say something more about web crawling. Namely, web crawling is the process of downloading and indexing data taken from the internet. But, not any kind of data — web crawling incorporates downloading and indexing specific data which is determined by keywords.

Of course, this process isn’t done manually. Web crawling is done by a specially designed program or an automated script called a web crawler, web spider, or spider bot.

What crawlers do

Web crawlers visit various web pages after a keyword, and a set of primary URLs are determined. Once a web crawler visits all these pages, it then continues to follow the available hyperlinks. These links typically include URLs to other web pages, so the crawlers redirect to new locations.

The primary purpose of web crawlers is to learn what different websites are about and store that information. The crawled websites are indexed, and they can be used whenever users need to retrieve some kind of information.

Because websites are filled with hyperlinks that lead to other pages, the web crawlers can visit different pages and follow their hyperlinks almost indefinitely. That’s why crawlers need to use algorithms that determine how frequently a website should be crawled and how many pages should be indexed.

How crawlers are designed

Now that you know what web crawlers are and how the web crawling process works, let’s take a look into the architecture of these programs and how they’re designed.


We already mentioned that web crawlers start from a list of familiar URLs. Then, they expand their crawling process by following hyperlinks that lead to other websites.

But, since the internet is constantly expanding and changing, it’s almost impossible for web crawlers to visit all the websites that exist on the internet. Therefore, web crawlers must prioritize which web pages they’ll visit next.

Prioritization is determined by an algorithm that calculates how often other pages link to a specific page, the number of visitors, and the likely amount of high-quality information. Webpages with plenty of backlinks and visitors typically contain valuable pieces of information, so they’re going to get prioritized.


As content on the web is frequently moved, changed, or updated, revisiting the already-crawled web pages is essential to index the latest information from the sources. Web crawlers also use algorithms for this, which decide how often a certain web page needs to be revisited.


Web crawlers have their limitations too. Each website contains a unique robots.txt file that specifies the rules and guidelines all bots on the website have to follow. Every web crawler will check these requirements before crawling to decide which pages it can crawl based on the robots.txt protocol. This means web crawlers won’t necessarily follow every web page and hyperlink, but they’ll still gather more than enough information from around the internet.

Value of web crawlers

Web crawlers are exceptionally valuable to companies due to their numerous different use cases and benefits. As more businesses become aware of their growing importance, the popularity of web crawlers is expected to increase in the future drastically.

Use cases

Web crawlers are flexible tools that can be beneficial to just about any industry. But, some industries and fields are already known for their advanced use of web crawling, including:

  • Data analytics and data science;
  • Marketing and sales;
  • Public relations;
  • Human resources;
  • Trading;
  • Technology;
  • Strategy.

Main benefits

So, what are the benefits companies can receive from web crawlers? Here are just some of the top advantages:

  • Generating leads;
  • Ensuring competitive pricing;
  • Content curation and analysis;
  • Keeping tabs on the competition;
  • Following brand reputation and social media presence;
  • Staying up-to-date with the newest industry trends.


All in all, it’s not necessary just to know what is a web crawler. To truly understand how these advanced software solutions work, one must be familiar with their architecture and crawling process. You can read the article here if you wish to learn more about crawling.

With insightful information obtained from this article, you’ll be able to make the most out of your crawling tools. From flexible use cases to numerous benefits, it’s easy to employ web crawlers once you truly understand how they work to deliver impressive results.

Charly bell

Hi there! I'm Charly Bell, a writer and explorer. I love sharing cool stuff about travel, health, business, finance, and much more in general topics. My aim is to provide informational articles so that maximum people will learn and educate themselves. I'm all about making it interesting and easy to understand. Join me on this journey, and let's explore together!

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