Web Scraping vs Web Crawling
Updated on June 4, 2021 | by Austin
The terms web scraping and web crawling are often used as synonyms to describe the same thing. However, even though they share some features, these two practices are used for entirely different applications. Both play critical roles in gathering data and competition monitoring, and they are often combined to provide the best results.
To be able to point out the differences, we have to explain each technique in detail and compare their applications for specific uses. If you still want to know what is a web crawler and how it’s different from a web scraper, keep reading, and we’ll tell you everything you need to know.
Also Read: Reasons For Choosing Hubspot CMS
What is web scraping?
Web scraping is a process of extracting data from a website, page, or multiple websites through automation. While it can be done by hand, the process would take too long, so instead, it’s done with special software tools designed to scrape information and content from websites.
Every web scraper analyzes the website first, finds the specific information you want, and downloads it in a readable format. All of the data extracted is precise and accurate, and web scrapers can be used offline to extract data from private servers and local connections. It’s mostly used to remove specific information, monitor competition websites, generate leads, job listings, and so on.
What is web crawling?
Web crawling is similar to web scraping, but instead of focusing the search on a specific website or page, crawlers extract information directly from the internet. The term crawling is used because it moves around websites similarly to how a spider moves around.
What is a web crawler?
Crawlers are mostly used by search engines such as Google, Bing, Yahoo, and many others for the purpose of web indexing. Web crawlers basically scan entire websites and create an index, allowing users to find the information they need quickly. A crawler is able to scan the entire website and extract information from deeper web pages, which are otherwise impossible to find. Crawlers use advanced bots to quickly navigate through tons of data and extract only the specific information you requested.
Similar but different
Both of these techniques are mostly used to find and extract specific information. However, there are some major differences between them. Here’s a quick overview of how they are used and what makes them different.
Scraping doesn’t have to involve the web
Web scraping is a technique that can be used offline. Special scraping tools can help you find specific information on a local machine or a private database. On the other hand, Web crawling always involves the internet and can’t be used on local machines. They can, however, extract massive amounts of data from the internet, including deeper layers that are unavailable during regular browsing.
The internet is full of content, and much of it is copied by numerous websites. Imagine a blog post that gets copied and posted on dozens of pages at the same time. When you use a web crawler, it will identify copied content and will only extract the information once. In other words, it will deduplicate the information to prevent data flooding. On the other hand, Web scrapers don’t understand copied content, which can lead to data duplication.
While both methods are used to extract information, they work on different scales. Data scraping can be done on any scale, while web crawling is only done on a large scale. Web crawling is great for handling large quantities of data, and everything it extracts is accurate and relevant.
How they are used
Naturally, web scraping and web crawling have completely different applications. Let’s take a closer look at where they are used the most.
Web scraping applications
Web scraping can be used for all kinds of specific situations, but it’s mostly used in retail marketing, equity research, and machine learning. In retail, it is often used to monitor competitors, prices, generate leads, gather customer reviews, all aimed to help business owners extract useful information. E-commerce platforms also use it for extracting images and product descriptions.
The method is also ideal for finding key information needed to make successful stock investments. You can quickly gather all market data to gain valuable insights into future trends. Lastly, it helps improve machine learning by generating tons of data. The machine will then crunch all data and identify patterns, gaps, and useful details.
Web crawling applications
Web crawlers are responsible for indexing information, and there would be no search engines like Google without them. They can find and accurately index information from billions of pages every day, which allows you to find what you’re looking for on Google quickly. Crawlers basically sort pages according to the quality of content, their performance, available functions, and so on. Their sole purpose is to find and generate accurate data.
As you can see, these methods are related, as they are both used to find specific information. With that said, they have entirely different applications and offer different results. It’s important to know that both of them are often used together to provide the highest quality of data possible. We hope that the article helped you understand the differences and similarities between web crawling and scraping.