Web crawler vs. web scraper: which tool best suits your data extraction needs? Our guide will help you make an informed decision.
Using a web crawler vs. web scraper for automating data extraction
With more than 64% of the global population logged in, each Internet user adds to the vast amount of data generated on the world wide web. Going through this data is a challenging task for researchers and data analysts. This is where web crawlers and web scrapers come in handy.
Web crawling and web scraping are two popular techniques used to extract data from the internet. Web crawlers and web scrapers are tools used to automate web data extraction. Although they can be used conjointly, they serve different data collection and extraction purposes.
To decide which data extraction tool is better for your data collection needs or to learn how to combine the two effectively, you need an in-depth understanding of web crawlers and web scrapers and how the two differ from each other.
This article aims to compare web crawling and web scraping by giving a comprehensive overview of both processes and providing readers with the main differences and similarities between web crawlers and web scrapers.
What is Web Crawling and How Does Web Crawling Work?
Web crawling is the process of using tools known as web crawlers (also known as web spiders) to archive or index all of the information on a web page. Web crawling relies solely on crawlers and cannot be done by hand.
Web crawlers navigate web data and process the target website from start to finish to index and organize the website content. Similar to a search engine, a web crawler scours website data to collect non-specific information. It extracts this information by indexing collected URLs.
The web crawling process entails finding and collecting URLs by following the links embedded on web pages. The crawler then analyzes these URLs and reviews the web pages, hyperlinks, and meta tags related to the collected URLs. The data found is then indexed and archived in a database as downloaded HTML files.
Some commonly used web crawlers include Google’s Googlebot, Amazon’s Amazonbot, and Bing’s Bingbot.
What is Web Scraping and How Does Web Scraping Work?
Web scraping is the process of extracting data from multiple websites and organizing it into distinct datasets manually or with tools called web scrapers. Although web scraping typically involves web scrapers, it can also be done manually.
Web scrapers work by automating data extraction from a website’s HTML code and then organizing that data into a comprehensible output that can be used for further analysis.
Similar to web crawling, web scraping also zeroes in on specific web data. Still, the main difference is that while web crawlers collect generic web data, web scrapers focus on entering target data into the scraper’s input field.
Some well-known web scrapers include Scrapy, Beautiful Soup, and ParseHub.
What are The Key Differences Between Web Crawling and Web Scraping?
Now that you are familiar with the web crawling and scraping process, it is time to examine the differences between these two data extraction methods.
Applications of Web Crawlers vs. Web Scrapers
The primary use of web crawling is its application in search engines. Search engines like Google and Bing can generate relevant search results in response to an input keyword by crawling the web. As explained earlier, web crawlers crawl web pages and the links embedded on those pages to find and index URLs.
Web scrapers are primarily used to extract specific information from web pages to run further analysis. Web scraping projects often use the results of data crawling to retrieve specific data sets from a website.
Retail marketing often uses web scrapers to gather data from rival companies’ social media platforms and websites. This gives businesses access to relevant data sets to conduct market analyses in order to maintain a competitive edge in their industry.
The use of web scraping in collecting data cannot be emphasized enough. With web scrapers, businesses can instantly retrieve information regarding competitor companies’ prices, products, reviews, and ratings. This enables businesses to conduct an accurate price comparison and develop a successful marketing strategy that aids in brand protection.
Businesses also use web scraping to decrease the cost of lead generation by scraping data from Google Maps and Linkedin to discover information about local businesses in a specific area. Along with this, scraping is often used by businesses for testing a company website’s internal links to spot broken or dead links in order to ascertain a website’s quality.
Search engines generally use web crawling on a larger scale. In contrast, web scraping is done on both small and large scales and is applicable in retail marketing, lead generation, and product data collection.
Data Outcomes of Web Crawlers vs. Web Scrapers
When it comes to web crawlers, the data outcome set generally comprises URLs.
Web scraping data outcomes consist of URLs, but they include further information like:
- product prices
- product reviews
- competitor product ratings
- customer reviews
- chronological search results
Advantages of Using Web Crawlers vs. Web Scrapers
Web crawler Advantages
- The web crawling process involves going through every single page corresponding to a keyword and indexing it. It is an automated process that makes it easier to collect information.
- Since web crawlers discover new links and add them to the crawl queue, web crawling can keep up with the constantly changing information on the internet. This makes crawling a great method to get an updated view of target datasets.
- Web crawlers are adept at managing the quality of content they go through and index, making them a reliable tool for data extraction.
Web scraper advantages:
- Web scrapers are handy when it comes to collecting data that is accurate. Scrapers remove the element of human error during gathering information, making them a dependable data extraction tool.
- Web scraping is an efficient way to gather data as it automates the extraction process and decreases the need to employ a large labor force. Using web scraping can significantly help lower production costs.
- Scrapers are built to pick out specific information and can be customized to find outcomes relevant to your data collection needs. For example, if you want to collect images, not text or videos, a web scraper can filter out irrelevant information and produce a pictorial outcome. Due to this, web scraping is able to make the data extraction process efficient and cost-effective.
What are The Key Similarities Between Web Crawling and Web Scraping?
Although web crawlers and web scrapers are separate data extraction tools, they share some similarities. For a fair comparison, these similarities also need to be considered.
Web crawling and web scraping come with their fair share of legal and ethical issues, with many websites having anti-scraping and anti-crawling policies.
In such cases, it is common for sites to use IP blocking to protect the crawling and web scraping of their contents. To overcome this issue, web scraping services are often equipped with proxy networks that provide real user IP addresses to prevent IP blocking.
Data crawling and web scraping are intensive processes that require labor and time. For companies that rely heavily on data, the cost of using a web crawler or web scraper can add on in the long run.
Limitations in Data Collection
Collecting data through web scraping and web crawling comes with its limitations. Along with sites having anti-scraping and web crawling policies, a target page could be difficult to access, with a set of IP blocks that cannot be circumvented. Both web crawling and web scraping face this limitation.
Web crawlers and web scrapers are both data extraction tools that play pivotal roles in streamlining the data collection process and making it more efficient.
Although often used interchangeably, web crawlers and web scrapers are separate extraction tools. Simply put, web crawling focuses on indexing data, while web scraping involves extracting specific data sets.
It is essential to be aware of the differences between web crawling and web scraping because it enables you to pick the tool best suited for your data extraction needs.
After going through this article, you should clearly understand web scraping vs. web crawling. You now have the adequate information needed to make a fair comparison of web crawlers and web scrapers and should be ready to know when to use which tool and how best to use it.
Frequently Asked Questions (FAQs)
Are web scraping and web crawling the same?
No, although they are both two methods of data extraction, web scraping retrieves select information from a target website, while web crawling indexes web pages based on the information they contain.
Is web scraping and web crawling legal?
It is generally legal to use web scraping and crawling tools as long as you aren’t violating the terms of service of the website you are scraping or crawling. However, laws regarding scraping and crawling can vary by countries and even states. In general, the legality of both processes depends on the data being collected, the source of this data, and how you intend to use it.
What are some of the best practices for web crawling vs. web scraping?
The best practices for web crawling and web scraping are similar. These practices include being aware and adherent to website terms of service, following ethical guidelines, and using reliable crawling and scraping tools.
Can websites detect web scraping and web crawling?
Yes, websites can detect web scraping and web crawling by monitoring IP address requests, analyzing traffic patterns, and recognizing a repeated user agent. Website administrators may also use CAPTCHAs or IP blocks to prevent web scraping and crawling.