How to Web Scrape without Getting Blocked
Web scraping is a tricky technique which is employed to retrieve large amounts of public data from the internet. A scraper is an extraordinarily convenient and rapid way to gather data as compared to manual scraping because of tons of data available in the digital space. The data is essential for research, to gain valuable insights about brands, businesses, and products. Big companies also scrape review pages and comment section as a part of their brand monitoring.
Data gathered through scraping offers plenty of benefits. However, scraping can overload web servers and prevent it, a lot of web admins equip their websites with anti-scraping measures. Their fight against data extraction ends up blocking the scraper, thus making large-scale crawling extremely difficult.
However, several strategies will help developers prevent a ban and keep their web scrapers undetectable. Continue reading to find out what they are.
Unblocked free proxies:
Scraping without proxies is nearly impossible. Servers rely on IP addresses to detect a bot or a web scraper. Many requests from a single IP address that is also extracting data from the site make the server suspicious, and if anti-scraping measures are in place, the IP will be automatically blocked.
IP address rotation is an effective way to perform web scraping, and it also makes it difficult for web systems to track them. Several methods will let you alter your outgoing address, such as using unblocked free proxies, shared proxies, VPNs, or any such software that provides anonymous communication.
Proxy servers will help you by hiding your system’s IP address and route your requests through a series of different IP addresses. Since your application will reach the target site through a proxy machine‘s IP address, instead of the scraping system’s IP, this will make the site believe that the call is generated from a different server. This will make it difficult for the website to differentiate between demands of crawlers, scrapers, and actual human users.
Apart from masking the original IP address, unblocked free proxies also help scrapers by getting past the rate limits of the target site. To curb the automated access and to augment the security, several sites incorporate rate limiting software. The software detects an abnormally large number of requests coming from a single IP address in a short time, and upon discovering the site returns to the user with an error message to block future requests for a limited period. Scrapers looking into thousands of web pages often run into rate limits and proxies help deal with this restriction. This way, the target site will receive fewer calls from a single IP which will remain under the rate limit, hence no blocking of the client.
Some proxy providers offer proxies free of cost. You could try these free proxies to get a taste of how it all works, however, be warned that using free proxies for web scraping is risky since these providers often sell user data to 3rd parties and can infect web pages with malware. They are also usually unstable and unreliable, so going with a paid alternative is highly recommended.
Private Proxies:
Private proxies are best for those who are in a serious commitment to web scraping. Several commercial proxy providers offer private proxies at an affordable rate. The proxies will let you rotate IP addresses and distribute the load across several exit points. They are managed by high-quality servers and offer swift and secure IP masking and IP rotation. These all minimize the chances of crawlers from getting traced and blocked.
On average, you will need 200 different proxy IP addresses. These will be sufficient to alternate 100,000 requests per hour by limiting 500 requests per hour from a single address. However, while spinning IPs, you will have to be vigilant to avoid bumping into rate limits. You can read more about the private proxy pool on Oxylabs.
Other Strategies:
Other approaches towards avoiding getting noticed and restricted include slowing down the crawling speed as the fast speed of the scraper often become a reason behind its detection. You should also use random programmatic delays and decrease the concurrent page accessing to give the impression of a human accessing the site. Moreover, to avoid blocking because of User Agent, the scraper should rotate user-agents and switch their frequency to reduce the risk of blocking.
The threat of getting restricted always looms over the graders; however, the ideas mentioned above will help you in steering clear of blocking. With the help of proxies, you can refine your existing strategies for crawling and scrape the renowned websites without being blacklisted, or IP banned.
