Web scraping is a massive industry with a great number of business applications, including data aggregation, machine learning, lead generation, etc. It provides access to valuable online data for companies.
However, getting information consistently and on a large scale is a big issue that web scrapers must navigate. Website owners often implement anti-scraping measures, such as CAPTCHAs and honeypots, to protect their sites from being scraped. They sometimes even block the IP addresses of those who violate these safeguards.
This is why there is such a demand for reliable proxies for web scraping.
This article will define proxies, discuss their utility in web scraping, and classify web scraping proxies into functional categories. Read on to learn about the inner workings of proxy servers, the various available types, their advantages, and how to use them.
What Is Web Scraping?
Web scraping is the process of gathering information from websites. It is often done with a web browser or an HTTP (HyperText Transfer Protocol) request.
The first step when web scraping is to crawl URLs and download the data from each page individually. The data retrieved is saved in a spreadsheet.
Setting up an automated system for copying and pasting data saves you much time. Companies can thus stay ahead of the competition by quickly extracting data from countless URLs based on their needs.
However, web scraping is a complex process. This is because websites are very diverse, which means that web scrapers must have a wide range of capabilities.
What Are Proxies?
A proxy server acts as a router or gateway for internet users. It aids in keeping a private network safe from cybercriminals. Proxy servers are sometimes referred to as "intermediaries" because they connect users to the websites they access.
Why Use a Proxy for Web Scraping?
Website scraping involves sending a high volume of queries to the server. This may trigger a reaction from the server against you, like blocking your IP address. In addition, some websites use techniques like request throttling and captchas to identify and thwart web scraping.
By sending queries through a proxy server, you can avoid detection by the website's anti-scraping defenses since it enables you to spread out your questions across several IP addresses, lessening the chance that you will activate anti-scraping protections.
In addition, using proxies for web scraping brings the following crucial benefits:
- With a proxy, you may change your IP address to one in any country, bypassing geo-restrictions.
- You can make multiple connection requests without risking being banned.
- Your data transfer and request times will improve as problems with your internet service provider (ISP) will be less likely to occur.
- Your crawling application may operate without issue and download data with no threat of being blocked.
You may break web scraping proxy servers into four groups depending on their intended use for proxy scraping: anonymity level, IP assignment method, IP assignment type (dedicated vs. shared), and protocol. Let's check out each of these.
By Anonymity Level
Depending on the proxy's level of anonymity, the website you're scraping may be able to tell your real IP address or whether you're using a web scraping proxy.
Transparent, Anonymous, and Elite are web scraping proxies by anonymity level.
When using a transparent (Level 3) proxy, your IP address is always reported to the destination server. As a result, the target website may immediately see that you're connecting through a proxy, making this method unsuitable for proxy scraping.
Level 2 (anonymous) proxies are preferable since they conceal the user's real IP address. The X-Forwarded-For header is instead set to the proxy's IP address or left blank. However, they continue to use the Via header, identifying themselves as proxies.
To prevent being blocked, use only elite (Level 1) proxies. The headers mentioned above are not set, and additional headers are also stripped out to prevent them from being identified as proxies.
It's important to remember that even elite proxies can be exposed. Most popular websites have extensive blacklists of IP addresses to which they will compare your proxy server's IP address. They can also examine your proxy's port to see if it is a standard proxy port, such as 8080 and 3128.
By IP Assignment Method
The second method of classifying proxies in web scraping is based on how their IP addresses are assigned. Proxy types by IP assignment method include Datacenter, Residential, and Mobile.
Datacenter proxies obtain their IP addresses from data centers managed by major cloud service providers like Amazon Web Services (AWS), Microsoft Azure (Azure), and Google Cloud Platform (GCP).
Individuals in their own houses host residential proxies. The customer's ISP provides the proxy’s IP address. The customers then agree to have proxy merchants utilize their IPs in exchange for payment or service (money, app/service access, etc.).
Lastly, mobile proxies are wirelessly linked mobile devices (like tablets and smartphones) that may act as proxy servers. Mobile carriers assign the IP addresses.
Like residential proxies, these devices belong to actual individuals. Their owners often install an application so that the device's bandwidths may be offered to the proxy network in exchange for payment.
By IP Assignment Type
The majority of proxy services provide both dedicated and shared proxies. You determine the one to choose based on your budget and your project's intricacy.
Private or dedicated proxies are set up for just one user at a time. Although they are less likely to get blacklisted, they are more expensive.
Multiple users can use shared proxies. As a result, it is more likely that some of them get blacklisted by major sites. They are more affordable than dedicated proxies.
The last way to classify proxies in web scraping is according to their protocol. Proxies classified by the protocol include HTTPS, SOCKS, and HTTP.
Once an HTTP proxy receives a request, it sends a new request to the destination server, collects the answer, and sends it back to the client. Their major drawback is that they aren't very safe. A malicious proxy might tamper with the response by, for example, inserting advertisements or a script that extracts cookies from the client's computer
HTTPS proxies function differently. If the client sends a particular CONNECT request, the proxy will establish an HTTP tunnel between the proxy server and the remote server. This makes the HTTPS protocol perfect for web scraping since it simply forwards all raw TCP data between the server and the client once the connection is made.
When compared to HTTP, SOCKS is a more basic protocol. It is quicker and more versatile because it only relays TCP communication between the server and the client. Therefore, it is perfect for resource-intensive uses like video streaming.
Managing Proxy Pool
- The request can be retried using a new proxy server if the current proxy encounters any difficulties (connection issues, blockages, captchas, etc.).
- Your proxy must recognize and bypass restrictions such as redirects, captchas, ghosting, blocks, etc.
- There must be control proxies. Some sites that need authentication insist on maintaining a constant IP address during a user's session; if the user switches proxy servers, they may be asked to log in again.
- Use random delay times and effective throttling to avoid detection by the website's anti-scraping measures.
- The proxy pool has to have a proxy set from the supplied geolocation, as certain websites may only accept IP addresses from certain countries.
- Note that low-quality public proxies are risky since they might infect your system and expose your web scraping activities if your SSL certificates aren't set up correctly.
How to Test Proxies for Web Scraping
Proxy testing for web scraping should center on three primary criteria: reliability, security, and speed.
Speed is a significant issue to think about while picking a proxy. A slow proxy may devastate your web scraping operations by increasing the likelihood of timeouts, unsuccessful requests, and delays. You may gauge the proxy's speed with the help of tools like cURL and fast.com, which offer a load time and performance score.
You should select a proxy with a low chance of going offline at inopportune times.
You should pick a proxy that keeps your data private and safe. Tools like SSL Labs and Qualys SSL Labs may be used to check a proxy's security. These tools will evaluate the SSL certificate of the proxy service for scraping and provide a security rating.
Try out several proxies until you find one that meets your reliability, speed, and security requirements for web scraping. However, you should also check the proxy's progress over time to ensure it keeps satisfying your needs.
How Many Proxies You Need for Web Scraping
To determine how many proxy servers you'll need to enjoy the perks of a good proxy, use this formula:
Number of proxies = Number of requests per second / Number of requests per proxy
For example, if you need to make 100 requests per second and each proxy can handle 10 requests per second, you'll need 10 proxies.
The user-selected target page(s) influences the number of access requests. It determines the frequency that an online proxy scraper crawls a webpage.
The crawling frequency may be measured in minutes, hours, or days, and it is constrained by the number of requests, number of users, and length of time that the target website permits. For instance, to distinguish between human users' and robots' queries, most websites only permit a certain requests or users each minute.
Tools for Testing Proxies and Web Scraping
A variety of tools exist for evaluating proxies and web scraping methods, such as:
Scrapy - a web scraping framework written in Python. It has in-built functionality to check proxies and deal with anti-scraping safeguards.
Selenium - powerful software for automating browser interactions and other online-related tasks, such as web scraping. It's useful for web scraping and proxy testing.
Charles Proxy - A web debugging proxy for testing proxies and monitoring web scraping actions. It has several tools for inspecting HTTP traffic and diagnosing problems.
Beautiful Soup - An HTML and XML parsing framework written in Python. You can use it with other web scraping programs to collect data from various websites.
Proxy servers are a useful web scraping tool, but it is crucial to choose the best proxy and test it extensively before using it.
By using the advice in this article, you can increase the effectiveness of your web scraping endeavors and safeguard your personal information online. No matter how much or how little experience you have with software development, there are many tools accessible that can help you optimize your web scraping project.
Happy Web Scraping and don't forget to check out my other articles: