What is Web Scraping?

Web scraping refers to the process of extracting data from websites. After collection, this information is typically exported into more convenient formats such as CSV or JSON. In most cases, CSV is preferred because it can be used in spreadsheets even by non-technical users.

Technically, web scraping can be done even by manually copying and pasting information from web pages. However, this approach is time-consuming and not feasible for large projects. Instead, web scraping is commonly performed using automated software tools called web scrapers. Their job is to collect data from the internet and convert it into a more structured format.

There are several types of web scrapers, each suited to different needs:

Custom scripts: Programs created by developers to extract specific data from specific sites. These are the most popular types of web scrapers.
Browser extensions: Add-ons or extensions installed in browsers that allow users to extract data from a page while navigating.
Desktop applications: Standalone software applications installed on a computer, offering an easy-to-use user interface and advanced features for visiting web pages in a local browser and retrieving data from them.
Cloud services: Web scrapers hosted in the cloud, which users can access and configure to achieve their data collection goals.

Regardless of the scraper chosen, collecting data from the internet is a challenging task. This is due to many issues that such tools face. But don't worry, we'll dive deeper into this topic later. For now, just keep this in mind.

Is Web Scraping Legal?

One of the most common myths about web scraping is that it is illegal. That's not true!

If you comply with CCPA and GDPR requirements, do not collect data behind login walls or data not publicly accessible, and avoid personal information, then it's fine. However, this doesn't mean you can scrape any site without rules. The entire process must be ethical, respecting the site's terms of service, robots.txt file, and privacy policy.

In short, web scraping is not illegal, but certain rules must be followed.

Use Cases of Web Scraping

Data is more valuable than oil, and what better source for valuable data than the internet? That's why many companies across various industries use information obtained via web scrapers to support their business processes.

There are dozens of possible use cases for web scrapers, but let's focus on the most common ones!

Price comparison. The idea is to use a web scraper to get prices for products from multiple retailers and e-commerce platforms, compare them, and make an informed purchase decision. This helps find the best deals, save time and money, and monitor competitors' pricing patterns.
Market monitoring. Web scraping can track market trends, product availability, and price fluctuations in real time. This gives businesses the ability to stay informed and respond quickly to the market. This data-driven approach allows companies to quickly develop new strategies, seize opportunities, and effectively respond to new user needs.
Competitor analysis. Extracting information about competitors' products, prices, promotions, and customer reviews gives a company insight into rivals' strengths and weaknesses. Programming scrapers to take screenshots of websites and marketing campaigns further enhances this analysis, helping companies develop plans to outperform competitors.
Lead generation. Web scrapers have forever changed the lead generation process. Where it used to take months and a lot of manual work, now contact information such as email addresses and phone numbers can be automatically extracted from various sources in minutes. Building a database of potential customers has never been easier.
Sentiment analysis. Web scraping facilitates sentiment analysis by extracting large amounts of user reviews from review platforms and public social networks. With this data, companies can study public opinion about their products, services, and brand. Understanding what people think helps improve customer satisfaction and proactively address emerging issues.

How a Web Scraper Works

How a web scraper manages to get data from a site depends on:

Nature of the target site: Sites with static content can be scraped using any HTML parsing libraries, while sites with dynamic content require a web browser.
Type of web scraper: Different scraping technologies require different approaches.

Generalizing how a web scraper works is not easy, but there are common steps that any web scraping process must follow. Here they are:

Connect to the target site: Use an HTTP client to download the HTML document associated with the target site's page, or instruct a headless browser to visit a specific page.
Parse or render the page: Pass the HTML content to an HTML parser and wait for it to complete, or wait for the headless browser to render the page.
Apply scraping logic: Program the web scraper to select HTML elements on the page and extract the desired data from them.
Repeat the process on other pages: Programmatically find URLs of other pages that need to be scraped and apply the above steps to each. This method is called web scraping and is used when the data of interest is distributed across multiple web pages.
Export the collected data: Preprocess the collected data to convert it to CSV, JSON, or similar formats. Then export it to a file or save it in a database.

After creating a web scraper or defining a task in a web scraping tool, it can typically be run locally, deployed on a server, or scheduled to run in the cloud.

Common Challenges in Web Scraping

As mentioned, scraping the web is not easy. Why? For many reasons.

First, the data extraction logic depends on the HTML structure of the pages. This means that whenever a site changes its user interface, it can affect the HTML elements containing the desired data, forcing you to update your web scraper accordingly. There is no real solution to this problem. The best you can do is use intelligent HTML element selectors that remain effective even after minor UI changes.

Unfortunately, the real problems are different and far more complex than maintenance. Let's dive into the real challenges of web scraping!

Second, most sites are aware of the scraping threat and protect their data with anti-bot technologies. These systems can detect automated requests and stop them, preventing your web scraper from accessing the site. Thus, your web scraper is likely to encounter the following obstacles:

IP bans: Many servers monitor incoming requests for suspicious patterns. When they detect requests from automated software, they blacklist the IP address for minutes or even permanently. This blocks automated requests before they can access the pages.
Geo-restrictions: Some countries have internal firewalls that prevent their citizens from accessing external sites. Similarly, foreigners cannot access all their sites. Additionally, some web pages change content based on the user's location. All this makes it difficult to collect information from such sites.
Rate limiting: If a web scraper makes too many requests in a short period, advanced DDoS protection or simple IP banning may kick in to prevent server overload.
CAPTCHA: If a user exhibits suspicious behavior or has low IP reputation, some sites display CAPTCHAs to verify if they are real users. Solving them in code is difficult, if not impossible, so they can block most automated requests.

Bypassing the above anti-scraping measures requires sophisticated workarounds that typically work inconsistently or only for a short time before being fixed. These obstacles reduce the efficiency and stability of any web scraper, regardless of the technology used.

Fortunately, there is a solution to this problem, and it's called a web proxy!

How to Avoid Blocks with Proxy Servers

A proxy server acts as an intermediary between your scraping process and the target sites. It receives your requests, forwards them to the target server, receives responses, and sends them back. In doing so, the site sees your requests as coming not from you but from the proxy server's location and IP address. This mechanism can hide your IP, preserve your reputation, and maintain your privacy by preventing fingerprinting.

The best providers offer a broad network of proxy servers spread across the globe, allowing you to overcome any geo-restrictions. By rotating requests through different proxies, your scraper can appear as a different user to the server each time, tricking modern rate-limiting and tracking systems. In short, proxies can overcome the most serious challenges in web scraping!

Whatever your goal, your web scrapers should always rely on some proxies to avoid blocks and ensure high efficiency.

Conclusion

From this article, you learned what web scraping is, what it's used for, and how it works. Specifically, you now know that this mechanism involves extracting data from web pages using automated software. As seen, this data extraction process from the internet applies to many scenarios and is useful for a wide variety of industries.

The main challenge is that websites employ all sorts of technologies to prevent web scraping and protect their data. Fortunately, all these technologies can be bypassed using proxies. Since there are dozens of proxy providers on the internet, you can save time by trying them all and immediately go with the best provider on the market.