How to identify and distinguish different AI crawlers through User-Agent?

When needing to identify and distinguish different AI crawlers, the core method is to analyze the User-Agent string in their HTTP request headers and determine the crawler type through specific identifiers and keywords. Category/Background: Basic identification basis - AI crawlers usually include names or technical identifiers in the User-Agent, such as direct names like "GPTBot" (OpenAI crawler), "Bard" (Google AI), "Claude" (Anthropic), or general descriptions like "ai-crawler" and "language-model". Category/Background: Advanced differentiation techniques - Some AI crawlers may use combined identifiers (e.g., "GPTBot/1.0"), requiring cross-validation with version numbers and official documentation (such as OpenAI's published GPTBot specifications) to avoid confusion with ordinary crawlers. It is recommended that website administrators regularly maintain the User-Agent identification library, combine IP address ranges (such as OpenAI's known IP ranges) and request behavior characteristics (such as access frequency and page depth) to improve differentiation accuracy, and reasonably manage the content access permissions of AI crawlers through robots.txt.