Web crawlers often face obstacles when navigating websites, encountering challenges that hinder their progress, even when utilizing proxy IPs. But what exactly triggers these setbacks? It's not about who divulged their identity or who notified the target website of their crawler status.

 

Websites typically discern whether a visitor is a web crawler or a legitimate user based on several criteria. Let's delve deeper into these identification methods:

1.Abnormal Access Frequency from a Single IP

During interactions on websites, users may receive messages like "Posting too quickly, please wait XX seconds" or "High-frequency access detected, please take a break." These prompts aim to ease server pressure, granting genuine users access to public data. However, web crawlers tend to exhibit more frenetic and rapid access frequencies than genuine users. Unusually high access frequencies from an IP may flag it as a web crawler, leading to restrictions on accessing public data.

2.Abnormal Data Traffic from a Single IP

Excessive data traffic from a single IP also raises suspicions. While download traffic on a download site is normal, excessive concurrent requests can overload servers, resulting in restrictions on accessing public data.

3.Repetitive Simple Website Browsing Behavior

Users have varying browsing speeds and habits. Some take seconds to browse a page, while others may take longer. Suspicion arises when multiple users from the same IP exhibit identical browsing speeds, accessing pages at consistent intervals. This behavior may lead to restrictions on accessing public data, even with proxy IPs.

4.Headers Verification

Websites also scrutinize headers, which play a crucial role in secure access. Parameters like User-Agent and Referer differ across browsers and are often overlooked by beginners. Absence or inconsistency in these parameters can easily lead to detection.

5.Linking to Global Residential IPs for Efficient Data Collection

Crawlers identify all page URLs, especially indiscriminate ones. Some websites embed links in CSS or JavaScript files, seldom accessed by normal users. These links serve as traps to catch crawlers, making them easily detectable.

Conclusion

These five points outline common methods used by websites to identify web crawlers. To evade detection, it's vital to address these criteria effectively and develop a robust crawler strategy. However, accessing data involves more than these methods, necessitating comprehensive research and analysis.

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