Before we begin, take a look at this short video - it's the scene from Harry Potter where he gets The Invisibility Cloak. It’ll help us better understand the concepts behind proxies.
Ready to know more about proxies for web scraping? Well, let's start with the most basic question.
Before you go and create your perfect proxy network, it's important to know what a proxy really means in web scraping terms? Once you know what it is, it will be obvious how it helps avoid the blocks.
Recall your networking class, an IP Address knows two things about you - your location and your Internet Service Provider. This is the reason why some over-the-top content providers can block certain content based on your geographical location. Voila, proxy!
A proxy is the invisibility cloak that hides your IP, so you can access the data seamlessly without getting blocked. When using a proxy, the website you are requesting no longer sees your IP address but the IP address of the proxy, giving you the ability to scrape the web with higher security.
Sounds very cool, right? Wondering how to get access to these proxies? The answer is a proxy server.
Going back to the video we watched earlier, a proxy server is the one who supplied this invisibility cloak to Harry. This intermediary server sits between you and the website. A proxy server assigns you a proxy, often from a pool of proxies, to seamlessly crawl the web. A proxy server handles your internet traffic on your behalf.
Now that you have access to these magical proxies and know exactly what they are, let’s dive into the ‘Why’.
Why is proxy the buzzword when it comes to web scraping? Well, scraping a well-designed and well-protected website at a medium to large scale could be quite challenging. The HTTP/HTTPS requests sent to the webserver can be blocked for various reasons. Remember the 4xx and 5xx status code responses you get while crawling the most visited e-commerce websites?
The most obvious reasons for these blocks could be
IP Geolocation: My favorite movie, The Lord of the Rings is not available on Netflix India. Now if the website recognizes you as someone trying to scrape content not available in your region or as a bot, they might not allow you to crawl their website to avoid overloading servers. If you really need that data for market research of your product or understanding how a new product feature is working in a particular region, you’d be in a real fix!
IP rate limitation- Almost every well-designed website has set certain limits on the number of requests they can allow from a single IP. Once you cross the threshold, you will get an error message and might even have to solve a Captcha so the website can distinguish between human and non-human activity. So beware before you send out thousands of requests to scrape an e-commerce website for your next price prediction campaign.
One solution to avoid these blocks would be using a pool of proxies rotating randomly. 🙂 Because you are sending requests with different IPs, the question of getting blocked does not arise at all! That is why proxies in scraping are so very important.
Proxies and proxy servers are by themselves legal. But you have to be careful. As long as your scraping logic complies with website instructions, robots.txt, and sitemaps, you have a green flag. It’s important to follow best practices in web scraping and stay respectful to the websites you are scraping. It's like the note in the video says, “Use it Well”.
Proxies also are meant to be used carefully and choosing the type of proxies should be thought through. Depending on the website you are trying to scrape, you can select between data center proxies, residential proxies, and many more. The ‘different types of proxies' topic is a rabbit hole in itself so we won't cover it here but you can always read all about it in this extensive guide on how to use proxies for web scraping.
Or if you want to take the easy way out, just use a proxy management solution where you can skip all the hassle and just focus on getting the data. I would highly recommend this if you are trying to scale your web scraping.