Do you know that failing to comply with data and privacy regulations might result in heavy financial penalties and legal consequences?
Do you want to go into all these complications or you want to extract data from your competitors’ website safely and without getting caught?
Web scraping is one of the most advanced data extraction techniques to get actionable insights from your competitors and public data available online. Once you get and convert unstructured, raw data into structured data, you can make data-driven, informed business decisions.
One of the main challenges businesses face is getting blacklisted while scrapping data from websites. However, you need to be smart while extracting data and you will not face such a challenge.
The million-dollar question is this- what are web scraping practices to evade blockers. This blog discusses various techniques that can help scrape data without getting blocked or blacklisted.
However, before that, let’s understand why websites block parties who try to scrape data.
Why Websites Block Scraping Activity?
You need to define “why” first to understand the concerns before getting into web scraping. Websites employ data privacy mechanisms not just to prevent others from fetching data, but for various other reasons. Let’s discuss some of them in brief.
Server Load and Performance Concerns:
When someone makes a request to a website, it consumes server resources. Sometimes, a few thousand requests from a single IP might slow down servers for authentic users. It might affect the website’s reputation. Furthermore, excessive scraping might also lead to increased hosting costs and poor user experience and performance.
Protecting Intellectual Property and Competitive Data:
Websites have invested their time and money on research and other web scraping activities to come up with published data. They consider such data as their intellectual property. Data like prices, product catalogs, inventory details, and content databases are valuable and represent significant investments. They obviously want such data to be protected from third-parties, especially from competitors.
Maintain Competitive Advantages:
Data is the new power in today’s cut-throat competition era. For example, in the eCommerce industry, data like pricings, inventory details, discounts & other offers, and customer reviews are very significant and present a 360-degree view on market trends and intelligence. By employing anti-scraping mechanisms, websites ensure that they don’t lose their competitive advantage.
Security Considerations:
Sometimes, automated web scraping tools might identify security vulnerabilities, while scraping websites. Also, they might attempt unauthorized access or execute denial-of-service attacks. Considering all these potential scenarios, websites have to implement blanket protections for security purposes.
Ad Revenue and Analytics Integrity:
Websites use key KPIs for advertising and other promotional purposes, including accurate user metrics. When the website is scraped through bots, it skews analytics, offering false data to websites to identify genuine users and bot traffic. Hence, they must employ anti-scraping mechanisms.
Preventing Data Misuse:
Sometimes, websites might prevent website scraping for third-parties because of potential unethical or harmful data use. Some of the unethical data use examples are spam list creation, unauthorized content sharing or selling, or building competing services.
Expert Tips to Avoid Getting Blocked While Scraping
Now you understand why websites employ anti-scraping mechanisms, let’s answer the main question: what are web scraping practices to evade blockers? We will discuss web scraping practices that might help you scrape data without getting blocked.
Use Proxy Servers
One of the most preferred website scraping techniques is to use proxy servers to hide your website’s IP address. These proxy servers act as intermediaries between your scraper and the website. It is the best way to prevent IP-based blocking.
There are various types of proxy servers like
- Residential Proxies: These proxies look like real ISP-assigned IP addresses and are hard to detect. However, using such proxies might increase overall overhead costs.
- Datacenter Proxies: these proxies come from datacenters and they are not as expensive as residential proxies. However, websites can easily identify them as bots.
- Rotating Proxies: Rotating proxies, as the name suggests, switch between different IP addresses, especially after a fixed number of requests or time intervals.
- Sticky Proxies: These proxies keep the same IP address for a certain amount of period, useful for tasks that require session persistence.
You don’t need to use one proxy for web scraping. Better rotate proxies from time to time to prevent from blocking. Also, you can use proxy pools with diverse geographic locations. Also, it is advisable to check proxies to identify and remove non-functional ones.
Randomize Browser Headers and User-Agents
When you generate an HTTP request, it has a header that provides information about the client. Websites generally analyze these headers to identify bots and prevent website scraping activities.
Some of the headers are:
- User Agents that identify the browser and operating system.
- Accept-Language that specifies language preferences.
- Accept-Encoding that indicates supported compression algorithms.
- Referer that shows the previous page the request came from.
Make sure that you implement these headers smartly. For example, you can maintain a list of different realistic user agents for different browsers like Chrome, Firefox, Safari, Edge, etc. Furthermore, you can also maintain a list of operating systems like Windows, Macs, Linux, Android, and iOS. Keep rotating them systematically to ensure that each session looks authentic and legitimate.
Slow Down Request Frequency
When boats request to websites, they are consistent and look unnatural. On the other hand, when human browsing patterns are somewhat different and irregular. Even if you are using bots, you can mimic human behavior by practicing following tips:
- Use random delays for requests and not use fixed intervals for requests.
- Analyze website behavior and limit requests per minute/hour accordingly.
- Analyze how users interact with pages and mimic similarly by not clicking all links in the same order.
- Always respect robots.txt to prevent getting blacklisted. Always follow it.
Maintain Stateful Sessions and Cookies
When you visit a website, they track your session using cookies and session IDs. If you ignore these mechanisms, they might find your activities suspicious. There are some session management practices you can follow like:
- Store and send cookies appropriately across different requests.
- If the website asks for login authentication, respect it and maintain login state.
- Many websites use Cross-Site Request Forgery tokens. You must extract and include them in subsequent requests.
- Make sure that you move through websites as a human with irregular clicks and random behavior.
Use Headless Browsers for Complex Websites
Today’s advanced websites are JavaScript-heavy and ask for full browser environments to load dynamic content. Here, you need to use Headless browsers as basic HTTP libraries will not be able to execute JavaScript. It is one of the web scraping limitations that must be considered.
Some of the use cases of Headless Browsers are:
- When you deal with JavaScript-Heavy websites.
- When landing pages require user interactions before displaying content.
- Websites that use sophisticated anti-boat measures.
- When you want to scrape applications with complex authentication flows.
Some of the tools that you can use for website scraping with Headless Browsers are Puppeteer, Selenium, and Playwright. Remember that Headless Browsers are resource-intensive and must be used when necessary.
Manage CAPTCHAs Strategically
We all come across CAPTCHAs while browsing websites. It is a simple technique to differentiate bots and humans, trying to interact with a website. They are not just designed to block bots, but to prevent any unauthorized access to users. However, there is no foolproof solution to CAPTCHAs, you can use some strategies.
- You can slow down the number of requests to avoid triggering CAPTCHA systems.
- Maintain consistent sessions to appear as legitimate users.
- You can also use residential proxies to mimic human behavior.
- You can use trained Machine Learning models to solve certain types of CAPTCHAs.
- For small web scraping projects, you can scrape manually.
- When you come across CAPTCHAs, switch to different IPs or pause the activity for sometime.
Respect Website Policies and Legal Boundaries
Keep yourself safe from legal and financial troubles by respecting website policies and legal boundaries. Complying to legal and data privacy regulations is crucial to avoid any unnecessary issues.
- Review the website’s terms of service for restrictions on automated data access.
- Check robots.txt before starting website scraping.
- Hire a legal counselor and discuss the legal framework related to automated website scraping.
- Comply with data regulation and protection laws like GDPR, CCPA, and others.
- Even if not explicitly prohibited, sending too many requests might be considered an attack.
Apply Different Scraping Patterns
- When you use multiple scraping patterns, it might help to keep your activities less detectable. Some techniques that you can use are:
- Alternate between depth-first and breadth-first crawling approaches to mimic human behavior.
- Scrape at different times of the day throughout a week to make it look like a human request.
- Use different proxies from different regions and vary request patterns accordingly.
- Vary your request strategy based on content on the page. For example, if you are extracting information from a product page, it might tolerate more frequent updates compared to a static page.
Switch User Agents
Though we have already discussed this, let’s dive deep into it to get a complete understanding. User agent strings notify websites about the browser and device information. When you use the same user-agent for thousands of requests it might be a red signal for websites.
It is important to switch user agents systematically. Here is a list of tips you can follow:
- Keep, maintain, and update a list of legitimate user agents.
- Match user agents with other headers. For example, an iPhone user agent should not have Windows-specific headers.
- Consider device-specific behavior as mobile browsers have different JavaScript capabilities and screen resolutions.
- Update your user agent list regularly.
Set a Real User-Agent
Though you can keep rotating user-agents, ensure that each user-agent is realistic and complete. Using generic and outdated user-agents might put you in a red-flag category.
There are online validation tools that you can use to test your user-agents. Also, you can check whether they are properly formatted and current.
Some Advanced Techniques and Considerations
To answer your question- how to scrape websites without getting blocked, we have added some advanced techniques for businesses in brief:
Implementing HoneyPot Detection
Some websites have invisible links or traps that are specifically designed to catch scrapers. You must learn to identify and avoid these to avoid getting blocklisted.
Behavior Analysis Evasion
There are various advanced anti-scraping techniques to block scrapers from data extraction. These advanced systems can analyze behavioral patterns beyond simple request rates. From tracking mouse movements to click precisions and scrolling behavior, they identify bots and you must be aware of them.
Keep Monitoring and Updating Your Strategies
You must implement comprehensive monitoring to detect any anomalies in targeted goals. Such monitoring must be so effective that you get notified when your scraping effectiveness decreases. Keep monitoring and keep updating your website scraping strategies.
Conclusion
Website scraping is a sensitive procedure and must be dealt with care. What are web scraping practices to evade blockers? Well, we have discussed almost all of them to give you a comprehensive view of technical difficulties and challenges and solutions. You can hire a professional website scraping company to build and implement an advanced website scraping strategy. Keep monitoring and updating your strategy, while keeping a sharp eye on details.
