Web scraping refers to the process of harvesting data or content from a website. It can either be manual or automated. Manual web scraping entails copying text or numbers from a site and pasting it on a search bar or a document on your computer. Ordinarily, though, the term web scraping is used when talking about the use of bots or programs, i.e., the automated form.
However, since web scraping entails harvesting data from websites, they have in-built measures to stop any data extraction. The anti-scraping techniques used include IP blocking, CAPTCHAs, honeypot traps, User-Agents (UA), and many more.
Although these techniques exist to prevent bots from accessing the sites to retrieve information, you can work around some of them. For instance, IP blocking, the most common anti-scraping tool, can be circumvented using proxy servers. Here’s how proxies’ functionality makes this possible.
What is a proxy?
A proxy/proxy server is an intermediary that acts as a gateway. The proxy stops web requests originating from a user’s PC, assigns them a new IP address, essentially hiding their real identity before directing them to the targeted web server on the user’s behalf. In short, the proxy takes the user’s computer’s place, thereby acting as a buffer that adds anonymity, security, and privacy. These three elements make proxies a must-have component whenever you are web scraping.
At the same time, there are numerous types of proxies, but only a few are suited for web scraping. This article provides guidelines that will help you choose the right type of proxy for extracting data from websites.
Why are proxies needed for web scraping?
Data can only be extracted from websites after making numerous web requests. In simple terms, automated web scraping entails asking – through requests – the web server to send an HTML document (the HTML version of a webpage). The web data harvesting tool subsequently goes through this document, in a process called parsing, to identify specific information that needs extraction.
This implies that a website with multiple webpages will require numerous data extraction requests, which the site will easily interpret as coming from a bot. As a result, it might either block the IP address or prompt the user to solve the CAPTCHA. Therefore, it is important to prevent these series of events from occurring using proxy servers – they are tailored for this.
Rotating proxy servers are the best type of proxies for web scraping applications. They either change the assigned IP address after every few minutes or give each web request a unique IP address. As such, they prevent a scenario whereby multiple requests seem to originate from a single device, which, as I have detailed earlier, triggers suspicion, ultimately culminating in IP blocking. Simply put, they prevent the anti-scraping techniques from coming into play.
Granted, rotating proxies are your best bet if you are to extract data from websites successfully. But they do not exist in isolation. Instead, you can only use them as either rotating residential proxies or rotating datacenter proxies. This, therefore, brings us to the factors you should consider when choosing between these two options.
Rotating residential proxies
Residential proxies assign residential IP addresses, which belong to internet service providers. Simply put, residential proxy service providers use existing users’ devices as the gateways. Thus, if you opt for residential proxies, your web requests will be routed through real users’ computers or laptops. The fact that the IP addresses are ever-changing means that your requests will go through multiple devices.
Rotating residential proxies may be slower than other types of proxies because they utilize existing users’ devices, some of which do not have the specs needed to be reliable proxies. However, using reputable proxy services like Oxylabs will not cause any speed issues because every residential proxy is carefully selected. Rotating residential proxies is ideal when extracting data from large websites.
Rotating datacenter proxies
A datacenter proxy is a virtual intermediary – located in the cloud – through which web requests go on their way to the target website. Datacenter proxy service providers assign datacenter IP addresses, which are generated by powerful datacenter computers. In this regard, rotating datacenter proxies have a vast IP address pool, implying that web scraping will always be smooth.
Rotating datacenter proxies are cheaper when compared to rotating residential proxies. They are also readily available. However, the downside is that they are easily flagged by websites, especially large websites because their bandwidth supports multiple requests at a go. For this reason, datacenter proxies are ideal when web scraping small websites.
Nonetheless, the fact that the IP addresses are not static implies that using rotating datacenter proxies is a surefire way of avoiding flagging. And that’s not all. Because they are cheaper than residential proxies and readily available, they are perfect for cost-effective and large-scale web scraping. However, success is only guaranteed if you choose a reputable proxy service provider.