What is Web Scraping?
What is web scraping? How does it work and how is it used? What are the pros and cons of web scraping? Similar questions keep coming up all the time. So this basic intro will lead you into the world of web scraping, then answer all questions that concern you.
What is Web Scraping?
Web scraping is an automatic method to obtain large amounts of data from websites. Most of this data is unstructured in an HTML format, which is then converted into structured data in a spreadsheet or a database to be used in various applications. There are many different ways to perform web scraping to obtain data from websites. These include using online services, particular APIs or even creating your code for web scraping from scratch. Many large websites, like Google, Twitter, Facebook, StackOverflow, etc. have APIs that allow you to access their data in a structured format. This is the best option, but other sites don’t allow users to access large amounts of data in a structured form or they are simply not that technologically advanced. In that situation, it’s best to use Web Scraping to scrape the website for data.
Web scraping requires two parts, namely the crawler and the scraper. The crawler is an artificial intelligence algorithm that browses the web to search for the particular data required by following the links across the internet. On the other hand, the scraper is a specific tool created to extract data from the website. The design of the scraper can vary greatly according to the complexity and scope of the project so that it can quickly and accurately extract the data.
How does it work?
There are two pieces to web scraping: the crawler and the scraper. The crawler, an artificial intelligence algorithm, follows internet links to browse the web for specific data. The scraper extracts data from the website and its actual design affects how accurately and quickly it works. Obviously, if the scraper is more specific in the data it targets, it is also faster.
As an example, you might want to scrape a consumer sales web page for the kinds of smartphones available. You certainly want the model numbers, but you probably don’t need customer reviews; limiting the scrape improves the speed.
This knowledge also helps detect and stop web scraping. Understanding the specific kinds of data scrapers are targeting on a site and how they are likely to target it helps to protect it.
There are several types of web scraping:
- Self-built or manual web scrapers. These demand sophisticated programming skills, but can also achieve many different goals and may be difficult to detect.
- Browser extensions. These are simply added to and integrated with a web browser, so they are limited by the browser itself.
- Cloud web scraping. These web scrapers run on an off-site server in the cloud, independent of local resources.
- Real-time or dynamic web scraping. This is the process of scraping data from sites as they change in real time.
Why is web scraping used?
Web scraping is used for a range of tasks. For example, it allows contact details or special information to be collected quickly. Scraping is commonplace in a professional context to obtain advantages over competitors. Data harvesting enables a company to view all of a competitor’s products and compare them with its own. Web scraping can also be helpful with financial data. The information is read from an external website, placed in a tabular format, and then analyzed or further processed.
A good example of web scraping is Google. The search engine uses the technology to display weather information or price comparisons for hotels and flights. Many common price comparison portals also practice scraping to show information from many different websites and providers.
Web Scraping Use Cases
Web scraping has a wide range of practical applications across various industries. Here are 10 everyday use cases:
- Price Comparison: Retailers use website scraping to monitor competitors’ prices and adjust their pricing strategies accordingly.
- Market Research: Businesses gather data on customer sentiment, product reviews, and market trends from websites and social media to make informed decisions.
- Content Aggregation: News aggregators and content websites automatically collect articles and posts from different sources to provide a centralized hub for users.
- Lead Generation: Sales and marketing teams scrape websites to collect potential leads or clients’ contact information (email addresses, phone numbers).
- Job Market Analysis: Job seekers and recruiters use internet scraping to collect and analyze data about job postings, salaries, and skill requirements.
- Real Estate Listings: Real estate agents and buyers scrape websites to gather information on available properties, including prices and location details.
- Weather Data: Meteorologists extract data from websites to analyze historical weather patterns and make forecasts.
- Stock Market Data: Investors and financial analysts scrape financial news websites and stock market data to make informed investment decisions.
- Academic Research: Researchers gather data from academic journals, repositories, and websites to support their studies and analyses.
- Travel Planning: Travel agencies and individuals scrape travel websites to compare prices, availability, and reviews for flights, hotels, and vacation rentals.
Is it legal?
One of the biggest myths about web scraping is that it is not legal. Well, this is not true!
As long as you comply with the CCPA and GDPR, do not collect data behind a login wall or that is not publicly available, and avoid personally identifiable information, you are fine. However, this does not mean that you can retrieve data from any site without any rules. The entire process must be done ethically, respecting the target site’s terms of service, its robots.txt file, and privacy policies.
In short, web scraping is not illegal, but you need to follow some rules.
How can companies block Web Scraping?
There are a few measures that prevent a website from being subject to scraping:
- Bot management: Using bot management solutions, companies can fine-tune which bots are allowed to access information on the website and which to treat as malware.
- robots.txt: Using the robots.txt file, site operators can specify which areas of the domain may be crawled and exclude specific bots from the outset.
- Captcha prompts: Captcha prompts can also be integrated into websites to provide protection against bot requests.
- Appropriate integration of telephone numbers and e-mail addresses: Site operators protect contact data from scraping by putting the information behind a contact form. The data can also be integrated via CSS.
- Firewall: Strict firewall rules for web servers also protect against unwanted scraping attacks.
Web Scraping vs Web Crawling
What is the difference between web scraping and web crawling? In brief, while web crawling is about discovering or finding URLs on the web, web scraping focuses on data extraction from one or more websites. The web scraping process typically combines web crawling and scraping.
And what is the difference between data scraping vs web scraping? Data scraping merely refers to detecting and extracting data, so essentially this is two ways of saying the same thing.
Conclusion
In this article, you learned what web scraping is, what it is used for, and how it works. Specifically, you now know that this mechanism involves retrieving data from web pages through automated software. As seen here, this online data extraction process applies to many scenarios and is beneficial to a wide range of industries.