AI Crawlers Robots.txt Guide: GPTBot, ClaudeBot and Search

A primary challenge in web administration is distinguishing between training bots, search crawlers, and live user request agents. Blocking every AI user-agent indiscriminately can wipe out site visibility across conversational search interfaces. Conversely, leaving directives entirely open allows foundation model creators to scrape content for future model pre-training without sending referral traffic back to the source.

Major AI developers assign separate user-agents to each function. For example, OpenAI uses different tokens for model training, search index updates, and live browsing requests. Understanding these splits helps webmasters tailor access rules based on strategic priorities.

• GPTBot: OpenAI’s main crawler for collecting data used to train future foundation models.
• OAI-SearchBot: OpenAI’s crawler dedicated to building index entries for ChatGPT search citations.
• ChatGPT-User: An agent triggered directly when an end user prompts ChatGPT to view a specific URL.
• ClaudeBot: Anthropic’s training crawler used to collect dataset material for Claude models.
• Claude-SearchBot: Anthropic’s specialized bot for gathering real-time web search index data.
• Claude-User: A live fetch token executed on demand when a Claude subscriber inputs a web link.
• PerplexityBot: A dedicated search index crawler for Perplexity’s answer engine.
• Perplexity-User: A direct request token active when a Perplexity user initiates a live site search.
• Google-Extended: A standalone rule token controlling Google model training without impacting AI Overviews.

Deciding whether to disallow training crawlers depends on content monetization models and visibility goals. For a content publisher relying on ad impressions, allowing training bots might mean providing value to LLM responses without receiving website traffic. However, blocking search bots like OAI-SearchBot or PerplexityBot stops answers from linking directly to site content as a live citation.

In a typical account strategy, web publishers often split their directives. They block heavy training crawlers such as GPTBot and ClaudeBot to reserve bandwidth and protect intellectual property. Simultaneously, they keep path access open for OAI-SearchBot and Claude-SearchBot so their content can be cited when users search for specific topics online.

Configuring the Training vs Search Split

To implement this split, explicit Disallow rules are set for training bots while Allow rules or open paths remain for search tokens. For instance, a news platform might restrict GPTBot across all directory paths while keeping OAI-SearchBot unblocked to capture referral links inside generated conversational responses.

Misunderstandings surrounding Google-Extended are common among web managers. Google-Extended functions as a control token that enables site administrators to opt out of having their content used for training Gemini and other Google foundation models.

Google-Extended is a token only and does not affect Google AI Overviews. Traditional Googlebot handles the crawl for search indexing and AI Overviews. Blocking Google-Extended will not prevent a website from appearing in AI-generated answer summaries within main search engine results pages.

If the goal is to completely exclude content from Google Search and AI Overviews, standard indexing directives like noindex tags or blocking Googlebot must be applied. Disallowing Google-Extended simply manages standalone model training participation.

Writing clear directives requires placing individual User-agent lines followed by explicit path permissions. AI crawlers respect standard robots.txt syntax, including Allow and Disallow statements, as well as path pattern wildcards.

Consider a Shopify store selling technical hardware. The store owner might want to prevent AI model training on proprietary user guides while permitting live customer search queries to crawl product specs. Defining explicit rules per bot token prevents unintended content blocking.

• Specify training bot directives: Set ‘User-agent: GPTBot’ followed by ‘Disallow: /’ to restrict OpenAI dataset building.
• Maintain search citations: Set ‘User-agent: OAI-SearchBot’ followed by ‘Allow: /’ to ensure ChatGPT search citations remain active.
• Handle Anthropic crawlers: Block ‘User-agent: ClaudeBot’ for training while keeping ‘User-agent: Claude-SearchBot’ enabled.
• Manage Google model tokens: Add ‘User-agent: Google-Extended’ followed by ‘Disallow: /’ if you wish to opt out of Gemini dataset ingestion.
• Set wildcard protections: Protect internal query directories or account pages by disallowing specific path routes like /cart/ or /search/ across all agents.

Relying strictly on robots.txt rules assumes that every automated crawler strictly obeys directives. While reputable services operated by OpenAI, Anthropic, Google, and Perplexity honor standard rules, verifying actual request patterns via server access logs ensures compliance.

Web admins can inspect Nginx or Apache server access logs to filter requests by user-agent strings. Identifying high request rates from specific IP ranges or string headers helps confirm whether crawler directives are being respected or if firewall rules need updating.

Steps for Verification

• Filter server logs by user-agent strings such as ‘GPTBot’, ‘OAI-SearchBot’, or ‘PerplexityBot’ to isolate crawl frequencies.
• Compare requested paths against your current robots.txt file to confirm blocked routes are not receiving status 200 server responses.
• Check reverse DNS or IP ranges published by AI vendors to verify that incoming traffic claiming to be OAI-SearchBot originates from authentic infrastructure.
• Use web application firewall custom rules to block rogue scrapers that spoof legitimate AI user-agent strings while ignoring Disallow commands.

At Alien Road, technical optimization strategies involve balancing content security with discovery across modern answer engines. Proper crawler segmentation protects server capacity and intellectual property while preserving brand exposure in AI search.