One of the main challenges which you may face while trying to scrape data from websites is the risk of your computer's IP address being blocked by the target website. Many websites employ anti-scraping measures to prevent automated data extraction. Additionally, you may prefer not to reveal your identity (network and computer details) with target servers while scraping data.
The best way to scrape data anonymously is to use Proxy Servers or a VPN . These tools help you avoid detection and prevent your IP address from getting blocked while scraping data.
How to avoid getting blocked while scraping data?
Inject Pauses During Mining
Web servers can easily detect scraping activity when continuous, rapid-fire page requests are received in a short period of time. Web Scrapers normally create a pattern of page requests which differ significantly from normal human browsing. Such patterns, like accessing hundreds of pages within seconds or ignoring site navigation, can trigger server-side security measures to flag and block automated traffic.
It is also unethical to place undue strain on web servers by sending automated, frequent page requests over extended periods of time. This behavior may violate the site's usage policies and terms of service, and can be considered irresponsible.
To avoid detection and to prevent unnecessary strain on the web server it is important to mimic human-like behavior when sending requests. This can be achieved by increasing the time interval between subsequent requests and by adding random delays (or pauses) during scraping.
WebHarvy allows you to add regular pauses while scraping data and also to mimic human behavior by adding random pauses (Human emulation mode). These can be configured in WebHarvy Settings > Miner.
Cookie / Session Management
Web servers can use cookies to detect automated scraping activity. The server assigns a unique cookie to each new user visiting its website. This cookie is stored locally by the browser and is used in subsequent page visits (requests). This helps the server to identify and track each user. Legitimate users of the website carry these cookies across multiple page visits, allowing the server to build a consistent usage pattern. However, many scraping scripts or software either ignore cookies or fail to maintain them properly thereby triggering alerts for suspicious behavior in the server.
WebHarvy's browser allows user session management using cookies just like a normal browser.
While using a rotating set of proxies, page requests appear to come from different locations (IP addresses) to the server. In this scenario, if they share the same cookie, it can create inconsistencies (like the same user ID appearing from multiple locations) which may raise red flags.
WebHarvy allows you to disable cookies while mining when proxies are used. See Disable cookies while mining option in WebHarvy Settings > Browser.
Proxy Servers & VPN
Proxy servers or VPN routes traffic from your web scraper through multiple intermediate servers, thereby masking your real IP address. You can use a single proxy server or list of rotating proxy servers for web scraping. There are also services where you specify a single proxy server address in software, but the traffic is routed through a different IP address for each request (rotating proxy service). Proxies when combined with cookie and session management makes your scraping pattern look more like that of multiple legitimate users instead of a single bot.
WebHarvy allows you to scrape data via proxy servers. You can configure either a single proxy or a rotating list of proxies to help mask your IP address and avoid detection.
Browser Fingerprinting
Browser fingerprinting is a technique used by websites to identify and track users based on the unique characteristics of their web browser. This helps web servers to distinguish between standard browsers (like Google Chrome, Microsoft Edge, FireFox, Safari etc.) and headless browsers used by web scrapers (puppeteer, selenium etc.).
Third party bot protection services such as Cloudflare, PerimeterX and AWS WAF are often employed by web servers to enhance website security. These services commonly use browser fingerprinting to identify and block users exhibiting automated or suspicious behavior.
WebHarvy's built-in browser is based on the Chromium open source project (Google Chrome core source code) and is continuously updated to bypass blocking mechanisms employed by the above services.
User agent detection is an integral part of browser fingerprinting. WebHarvy allows you to set a custom user agent string for its built-in browser. The dropdown option at Settings > Browser > Enable custom user agent string, allows you to select a standard browser's user agent string (Chrome, Edge, Firefox, Safari etc.).
How to recover after a website blocks your IP?
If your scraper has already been blocked by the target website, the following are some steps which you can try to recover from the block.
- 1. Delete the local browsing history, cookies stored by the browser used by your web scraper. In WebHarvy, you can go to Settings > Browser and click on the 'Delete Cache / Browsing History' button.
- 2. Use a standard user agent string for your browser. WebHarvy allows you to paste or select user agent strings in Settings > Browser > Enable custom user agent string option.
- 3. Disable cookies before resuming mining. Select WebHarvy > Browser > Disable cookies while mining option.
- 4. Use proxy servers or VPN to connect to the target website anonymously.
- 5. Use a different network to access the internet.
How to obtain proxy server addresses ?
Proxy servers, both paid and free, are widely available online and can be found through a simple Google search.
However, free proxies are often slow, unreliable and prone to frequent disconnections, which can interrupt or prematurely terminate the scraping process. For this reason, we do not recommend using free proxy servers.