Advanced Web Scraping: Protected & Large-Scale Sites

Complex Website Scraping: What Makes a Website “Complex”?

Advanced web scraping of complex sources requires a different approach from standard extraction — both the tooling and the project architecture need to match site’s specific characteristics. 93% of organizations plan to increase their budgets for data collection, and a growing share of that investment goes toward sources with layered defenses. We divide “complex” websites into three categories:

• Large web sources
• Protected sites
• “Weak” or old websites

A single website can fall under more than one of these categories. Let’s dive into each type and see how they can be scraped.

Advanced Web Scraping: Large-Scale Sources

Websites with a lot of web pages (usually more than one thousand) are considered large. Big e-commerce sites or social networks fall into this category. If you want to scrape data from this kind of website, you will probably face the following difficulties:

Scraping Data from Website with Inconsistent HTML

It happens because large sites, as a rule, get large gradually and contain as many old pages as new ones. Different programmers can work on these websites at different times. To scrape the same field (e.g., “service name”), we have to develop different parsers for particular pages.

This process requires a good data quality assurance process to find incorrect data and check the HTML code of each web page. Because target sites change frequently, DataOx offers scraper maintenance and support to keep your extractors accurate and operational long-term.

Pagination, Lazy Loading, and Website Scraping Tool Limits

To scrape large websites, web crawlers have to go from one page to another. If sites have pagination (like most ecommerce websites have), you need to consider sorting and other nuances related to it. Lazy loading, when items load as you scroll down a page, can cause a lot of headaches. A lot of duplicates may occur in such cases.

Website Scraping Services for Protected Sources

CAPTCHA and location limitations are the simplest way to protect a website from data scraping. But such protection is relatively easy to avoid. CAPTCHA solving services are software that send a simple puzzle to a human user who recognizes it and returns results to the scraper. Proxies help to avoid location IP blocking

Read more about that in our blog if anti-bot handling is the main obstacle —> Web Scraping Challenges and How to Overcome Them

DataOx has faced exotic restrictions on a “complex” Canadian website that limited the hours of its website like a brick-and-mortar shop.

There is a category of websites in which owners order special protection from third-party vendors (like Imperva or Akamai). Such services create heavy restrictions on the amount of data you can extract from the website. They have special algorithms that “understand” that the web scraper is not human, but rather an automated process.

Good examples of such web sources are LinkedIn, Glassdoor, British Airways, and others. Generally, the sites that are extremely often scraped, tend to have extremely advanced anti-scraping mechanisms.

Such sites should be scraped respectfully, but it does not mean you won’t be banned. However, different tools and tricks can help to avoid this: human-like crawling, user agent rotation, and proxy rotation. When off-the-shelf website scraping tool cannot handle heavy anti-bot protection, DataOx builds custom website data scraping software from the ground up for your specific sources.

Advanced Web Scraping Techniques: User-like Behavior

The best way to pretend your scraping bots are real users is to use a real browser. Besides, try not to crawl in a predictable and repetitive way. Scraping content in sequence increases your chances of being identified by the bot protection mechanisms of the target site. That’s why the orders should be randomized as much as possible as well as delays between requests. It’s also advisable not to chain all the requests in one large sequence. Keep in mind that the more unpredictable your scraper is, the more it’s human-like and the more likely it’ll operate successfully.

User Agent Rotation

The main trick in parsing a website that does not want to be parsed and tries to prevent its content theft, is to write unidentifiable script and randomizing user agents.

Proxy Rotation

Multiple requests from the same IP are the main identifier that a site is being scraped.

A proxy rotation service can help you eliminate this issue by changing IP addresses with every request you make. Depending on the project tasks and budget, either Datacenter or Residential IPs can be chosen.

It’s very difficult to extract large volumes of information from complex sites, but we know how to do it. At DataOx, we develop a lot of workarounds using human behavior imitation, proxy rotation mechanisms, and “careful” scraping. Companies that need continuous coverage of protected sources often choose to outsource web scraping development to a dedicated team rather than maintaining in-house infrastructure.

Scraping Data from Website with JavaScript & Anti-Bot Protection

Modern single-page applications built on React, Angular, or Vue.js render content after the initial HTML response. Because of the render, a plain HTTP request returns a content full of gaps. Scraping these sources requires a headless browser (Playwright or Chromium) that executes JavaScript before parsing. This is one of the more demanding advanced web scraping scenarios because the technical stack is heavier, and most heavily JS-reliant sites also perform bot detection layers.

Websites use JavaScript to create dynamic and interactive experiences. These single-page applications load content automatically without refreshing the page, which complicates website data scraping: traditional scrapers that extract raw HTML often miss data generated by JavaScript after the page loads.

Sites that combine JavaScript rendering with Cloudflare, DataDome, or Imperva require coordinated handling: fingerprint patching, TLS impersonation, and behavioral randomization applied at the same time.

Go deeper on Cloudflare protection in our article —> Scraping Cloudflare-Protected Websites: Challenges & Methods

Scrape Dynamic Website Content: Monitoring and Freshness

Dynamic Data is another category of information which is difficult to scrape since you have to deal with the information that changes very often. Yet monitoring dynamic data streams allows better insights and faster actions based on the information received up-to-the-moment. In such a way, the time between cause and effect can be significantly reduced.

Through a continuous dynamic data extraction with search engine bots and other tools one can receive a comprehensive and high-volume database, however, data is often a time sensitive asset in such a case, so it’s vital to process it, analyze it, and act on it quickly. That’s why it’s vital not only to have reliable and matching storage for the data scraped, but also effective tools and mechanisms for its further usage.

What Is Scraping a Website That Is Weak or Outdated?

There are websites that fall in the “complex” category but are easy to break and web scrape. These web sources were usually made a very long time ago or were not built for a lot of visitors. The major problem with scraping such websites is the risk of breaking the website due to the weak servers. For instance, if the website capacity is 1,000 simultaneous visits, but our scrapers exceed it to 1,001, the website will be down. To avoid that, the research as a first stage is essential.

Curious about the end-to-end process? Read more about how DataOx handles complex scraping projects from discovery to delivery.

To summarize, “complex” websites can affect the amount of data you can get from them in a particular period. Complex anti-bot bypass work varies by source — visit our page for a full overview of the cost of web scraping services and what drives project pricing.

What else is important, we know that redundant data can be a real problem, particularly when you extract at a large scale. So, we take care to deliver cleaned and accurate data to our clients, removing redundant, duplicate, irrelevant or faulty information from the datasets we provide to them.

DataOx acts as a data delivery service. You get data clean, accurate, and up-to-date sent to you once or scheduled, or our scraping experts can help you to develop a custom solution for web scraping complex websites. Just schedule a free consultation.