Which AI crawlers should I allow in robots.txt? GPTBot, PerplexityBot, etc.

Here’s the comprehensive breakdown:

Major AI crawlers and their purposes:

My recommendation for most B2B sites:

Allow all of them.

Why:

1. AI visibility drives qualified traffic
2. Being cited builds brand authority
3. Blocking puts you at competitive disadvantage
4. The “content theft” concern is mostly theoretical

When blocking makes sense:

• Premium/paid content you sell
• Content licensing negotiations in progress
• Specific legal requirements
• Competitive intelligence you don’t want shared

For your legal team: “Our content is already publicly available. Blocking AI crawlers only prevents us from being cited, not from being read. Competitors who allow access will capture the visibility we lose.”

Let me help you talk to legal:

Legal’s concerns (valid but misplaced):

1. “They’re using our content without permission”
2. “We lose control of how content is used”
3. “We might have liability if AI misrepresents us”

The responses:

1. Content usage: Our content is publicly accessible. Robots.txt is a request, not a legal barrier. Content in training sets predates our blocking. Blocking now doesn’t remove existing data.

2. Control: We never had control over how people use publicly available content. AI citation is functionally similar to being quoted in an article. We want citations - it’s visibility.

3. Liability: AI providers take responsibility for their outputs. There’s no established case law creating liability for cited sources. Not citing us doesn’t protect us - it just makes us invisible.

The business case:

• Blocking: Lose visibility, protect nothing
• Allowing: Gain visibility, risk nothing new

Proposed policy language: “We allow AI crawler access to maximize visibility for our publicly available content. We reserve the right to revise this policy if content licensing frameworks evolve.”

This gives legal a policy on paper while keeping you visible.

You don’t have to be all-or-nothing. Here’s selective blocking:

Block specific paths, allow others:

User-agent: GPTBot
Disallow: /premium/
Disallow: /members-only/
Disallow: /proprietary-data/
Allow: /

User-agent: PerplexityBot
Disallow: /premium/
Allow: /

When selective blocking makes sense:

• Premium content sections
• Gated resources (even though already gated)
• Competitive analysis you don’t want shared
• Pricing/internal strategy docs (shouldn’t be public anyway)

Our setup:

• Allow crawlers on 90% of site
• Block on premium content areas
• Block on internal documentation
• Full visibility on marketing/SEO content

The benefit: Gets you AI visibility where you want it, protects sensitive areas, gives legal something to point to.

Here’s how to see what’s actually hitting your site:

Log analysis setup:

Look for these user-agent strings:

• GPTBot/1.0 - OpenAI training
• ChatGPT-User - Live browsing
• PerplexityBot - Perplexity
• Google-Extended - Gemini
• ClaudeBot/1.0 - Anthropic

What we found on our site:

• PerplexityBot: Most active (500+ hits/day)
• GPTBot: Periodic comprehensive crawls
• ChatGPT-User: Triggered by actual user queries
• Google-Extended: Follows Googlebot patterns
• ClaudeBot: Relatively rare

The insight: PerplexityBot is most aggressive because it’s real-time retrieval. GPTBot is less frequent but more thorough.

Monitoring recommendation: Set up dashboards to track AI crawler frequency. Helps you understand which platforms are paying attention to your content.

Beyond the big ones, here are other AI-related crawlers:

Additional crawlers to know:

The Common Crawl question: CCBot collects data that ends up in many AI training sets. Some argue blocking CCBot is more effective than blocking individual AI crawlers.

My take:

• Block CCBot if you want to limit training inclusion
• Allow specific AI crawlers for real-time visibility
• This gives you some training protection while maintaining live visibility

Reality check: If your content has been public for years, it’s already in training data. These decisions affect future crawls, not history.

One factor nobody’s mentioned: crawler impact on site performance.

Our observations:

• PerplexityBot: Can be aggressive (rate limiting sometimes needed)
• GPTBot: Generally respectful of crawl delays
• ChatGPT-User: Light (query-triggered, not bulk)

If you’re seeing performance issues:

Use crawl-delay in robots.txt:

User-agent: PerplexityBot
Crawl-delay: 10
Allow: /

This slows them down without blocking.

Rate limiting approach:

• Set crawl-delay for aggressive bots
• Monitor server load
• Adjust as needed

Don’t confuse rate limiting with blocking: Slowing crawlers protects your server. Blocking crawlers eliminates your AI visibility.

Different goals, different solutions.

Think about this competitively:

What happens if you block and competitors don’t:

• They appear in AI answers, you don’t
• They capture brand awareness, you don’t
• They get AI referral traffic, you don’t
• They build AI authority, you don’t

What happens if everyone blocks:

• AI systems find other sources
• Nobody wins, but nobody loses to each other

What’s actually happening: Most companies are NOT blocking. The competitive disadvantage is real and immediate.

The game theory: If your competitors allow access, you should too. The visibility game is zero-sum for competitive queries.

Check your competitors:

1. Look at their robots.txt
2. Test if they appear in AI answers
3. If they do, you’re falling behind by blocking

Most B2B companies I’ve analyzed: Allow AI crawlers.

This gave me what I need to make the decision. Here’s my recommendation to leadership:

Proposed robots.txt policy:

Allow:

• GPTBot (ChatGPT training)
• ChatGPT-User (live browsing)
• PerplexityBot (real-time retrieval)
• Google-Extended (Gemini training)
• ClaudeBot (Claude training)
• Applebot (Siri)

Selective block paths:

• /internal/
• /drafts/
• /admin/

For the legal team:

“We recommend allowing AI crawler access because:

1. Our content is already publicly accessible
2. Blocking prevents visibility, not content usage
3. Competitors who allow access will capture our market position
4. Content in existing training sets isn’t affected by blocking

We’ve implemented selective blocking for internal content that shouldn’t be public anyway.

We’ll monitor visibility using Am I Cited and revisit if content licensing frameworks evolve.”

Next steps:

1. Implement updated robots.txt
2. Set up AI visibility monitoring
3. Report on visibility changes quarterly
4. Revisit policy annually

Thanks everyone - this was exactly the context I needed.