First, we need to distinguish between the three different uses, and then we can discuss whether to open or close them.
The first category is for training: collecting content for model training, such as GPTBot and ClaudeBot. This essentially means preventing the bot from using content in future training datasets, but it doesn't prevent the use of content that has already been trained or content that has been republished by third parties. The second category is for search indexing: creating indexes and source links for AI search, such as OAI-SearchBot and PerplexityBot. This effectively prevents the bot from being able to search within that platform. The third category is for user agent: real-time fetching of specific URLs when users request it during a conversation, such as ChatGPT-User and Perplexity-User. According to Perplexity's official documentation, these requests are considered user behavior and are generally not subject to robots.txt control. Blocking them requires server-side measures. There are also two exceptions: Google-Extended and Applebot-Extended are not independent crawlers, but rather control codes in robots.txt, which control whether content can be used for training Gemini and Apple's models, respectively. In reality, Googlebot and Applebot are still used to fetch the content.
Main AI Web Scraping Tools
Based on the official documentation provided by each platform (definitions of usage are based on the official documentation, and may be updated according to platform policies):
The primary impacts of AI-powered web crawlers and blocking techniques| Name | Affiliation | Category | The primary effects of the blockade |
|---|
| GPTBot | OpenAI | Training | This content should not be used for model training; it will not affect ChatGPT's search functionality. |
| OAI-SearchBot | OpenAI | Search index | Remove the source links from the ChatGPT search. |
| ChatGPT-User | OpenAI | User agent | The user was denied access when attempting to read the data. |
| ClaudeBot | Anthropic | Training | This content should not be used for training Claude. |
| PerplexityBot | Perplexity | Search index | Identifying the Sources of Perplexity |
| Google-Extended | Google | Training control code | Not intended for use with Gemini; does not affect Google Search or AI Overview. |
| Applebot-Extended | Apple | Training control code | Not for use in training Apple models. |
| Amazonbot | Amazon | Index/Assistant | Usage of services like Alexa is restricted. |
| CCBot | Common Crawl | Public datasets | Exit Common Crawl (a major source of training data for many models) |
Decision-Making Framework: Analyzing the Business Model of the Content
The axis of judgment is "What you gain and lose when AI processes the content." Public marketing content (service descriptions, case studies, articles): The purpose is to be discoverable, with open search and user-agent models posing minimal risk. Training models should align with the brand's perspective. Paid content and original databases: The content itself is the product. Blocking training models is a reasonable default. For search models, the value of driving traffic should outweigh the risk of content leakage. Media and publishing: Negotiation and licensing are key considerations. Blocking is often part of the negotiation strategy. Common principles: This is a reversible policy decision, not a one-time technical decision – first choose a position and review it every quarter.
Our selection criteria: Comprehensive openness, with the following reasons:
This website's robots.txt file allows access to GPTBot, OAI-SearchBot, ChatGPT-User, ClaudeBot, PerplexityBot, Google-Extended, Applebot-Extended, and Amazonbot. The reason is straightforward: we are a B2B service website, and the sole purpose of our content is to allow potential clients to find us and determine whether we are trustworthy. AI platforms referencing our content to answer user questions provides exposure for us, rather than causing a loss. Furthermore, we use the "noindex" directive within the page hierarchy for pages that we do not want to be indexed (such as drafts and personal pages), rather than using robots.txt. The difference between these two mechanisms is explained in the next section.
Practical details and common mistakes
The first common mistake: treating robots.txt as a privacy tool. robots.txt only blocks web crawlers from accessing specific files; it is not a mechanism for controlling access to sensitive content, which requires login and permission protection. Second: confusing crawling and indexing. robots.txt blocks crawling; to prevent a page from being indexed, you should use the "noindex" tag. However, pages blocked by robots.txt are not even able to read the "noindex" tag. Third: blocking the wrong target. Blocking Google-Extended does not affect search results, but blocking Googlebot directly removes the page from search results. You should always verify the robots.txt settings using Google Search Console (GSC) before and after making changes. Fourth: misconfigured Web Application Firewalls (WAFs). WAF rules may block crawlers while allowing access to specific files, requiring verification of actual access through server logs and official IP lists.
