This occurs because keyboard behavior is also one of the detected factors. Metrics such as the time difference between key presses and releases, as well as the intervals between two consecutive keystrokes, are used as evaluation criteria. These parameters need to be properly adjusted manually.
When real users type, the time intervals between keystrokes vary. Familiar words are typed faster, while unfamiliar ones are typed slower. In contrast, when using web crawlers, the intervals between keystrokes may be uniform, which significantly differs from real user behavior and can trigger detection mechanisms. Additionally, real users may make typing errors, leading to deletion or correction actions—a behavior often overlooked by automated scripts.
The time difference between pressing and releasing each key also varies and is not fixed. If a crawler simulates keystrokes with fixed press-and-release durations, it can be detected.
How to Resolve This Issue?
To avoid detection, simulate real user behavior more comprehensively. For instance, generate non-uniform keystroke intervals and emulate user actions such as deleting and re-entering text.