Google-Extended vs Googlebot: What Website Owners Need to Know (2026)

Google operates many different web crawlers, and understanding the difference between them is very important for your website strategy. The two that website owners confuse the most are Googlebot and Google-Extended. They have similar names, but they do completely different things. Getting them mixed up can have serious consequences for your traffic.

Blocking Googlebot by accident removes your website from Google Search. Blocking Google-Extended only affects your visibility in Google's AI features. These are two very different outcomes, and you need to know which one to target. This guide explains both crawlers in detail and helps you make the right decision for your website.

This guide is for website owners, SEO professionals, and anyone who manages a website's robots.txt file. By the end, you will know exactly what each Google crawler does, how they interact with your website, and which ones you should block or allow based on your goals.

What is Googlebot?

Googlebot is Google's main search engine crawler. It has been around since the early days of the internet, and it is the most well-known web crawler in the world. Googlebot's job is to visit websites, read their content, and send that information back to Google so it can be added to the search index.

When Googlebot visits your website, the following things happen:

• It reads your page content (text, images, links, structured data)
• It follows links to discover other pages on your site
• It renders your pages using JavaScript (for modern websites)
• It sends the data to Google's indexing system
• Google uses the data to rank your pages in search results

Googlebot uses the following user-agent strings:

Critical warning: You should almost never block Googlebot. If you add User-agent: Googlebot with Disallow: / to your robots.txt, your website will be removed from Google Search results. This means no one will find your site through Google. This is the single biggest mistake you can make with robots.txt, and it is surprisingly common.

We have seen many websites where someone meant to block Google-Extended (the AI crawler) but accidentally blocked Googlebot (the search crawler) instead. Always double-check which crawler you are targeting. Use our Robots.txt Validator to verify your rules before uploading them.

What is Google-Extended?

Google-Extended is Google's AI training crawler. Google introduced it in September 2023 to give website owners a way to control whether their content is used for AI purposes. While Googlebot collects content for search indexing, Google-Extended collects content for training Google's AI products, specifically Gemini and Google AI Overviews.

Here is what Google-Extended does:

• Collects publicly available content from your website
• Sends the content to Google for use in AI model training
• Your content may appear in Gemini responses and AI Overviews
• Follows robots.txt rules (you can opt out by blocking it)
• Does NOT affect your Google Search ranking in any way

In robots.txt, you target Google-Extended like this:

The most important thing to understand is that Google-Extended and Googlebot are completely separate systems. They share the same company (Google), but they do different things. You can block one without affecting the other. Many websites block Google-Extended while keeping Googlebot allowed, which lets them stay in Google Search results while opting out of AI training.

Google-Extended is especially important because of its connection to Google AI Overviews (the AI-generated answer box at the top of some Google search results). If you block Google-Extended, your content will not be used in these AI summaries. This matters because AI Overviews are appearing on more and more Google search result pages in 2026.

Side-by-Side Comparison

Let us put Googlebot and Google-Extended side by side so you can clearly see the differences:

As you can see, these two crawlers have very different impacts. The key takeaway is: never block Googlebot unless you want to disappear from Google. Blocking Google-Extended, on the other hand, is a perfectly normal choice that many websites make to protect their content from AI training.

You can check the status of both crawlers on your website using AI Crawler Check. The tool shows you whether Googlebot and Google-Extended are blocked, allowed, or partially restricted. It also shows all other 154+ bots at the same time.

Google AI Overviews: Why Google-Extended Matters More Than Ever

Google AI Overviews (previously called SGE, which stood for Search Generative Experience) is Google's AI-powered answer feature. When you search for something on Google, you may see an AI-generated summary at the very top of the results page. This summary is created by Google's AI using content from multiple websites.

In 2026, Google AI Overviews appear on a growing number of search queries. This makes the decision about Google-Extended more important than ever. Here is why:

The same applies to Gemini, Google's AI assistant. Gemini uses content collected by Google-Extended to answer user questions. If you block Google-Extended, Gemini will be less likely to mention or recommend your website.

The decision about Google-Extended is similar to the decision about GPTBot (OpenAI's crawler). Both are training crawlers from major AI companies. The difference is that Google-Extended is connected to Google's search ecosystem, which makes it unique. Blocking GPTBot only affects ChatGPT. Blocking Google-Extended affects both Gemini and Google AI Overviews, which appear right inside Google Search.

All Google Crawlers You Need to Know

Google has more than just Googlebot and Google-Extended. Here is a complete list of the Google crawlers that matter for website owners in 2026:

As you can see, Google-Extended is the only Google crawler you can safely block without affecting your regular Google Search presence. All other Google crawlers are connected to search features that you probably want to keep.

For full details on every Google crawler, visit the Google bots section in our Bot Directory. Each bot has its own page with user-agent details, blocking instructions for robots.txt, Nginx, Apache, and meta tags.

Choosing Your Google Crawler Strategy

Now that you understand the difference between Googlebot and Google-Extended, let us look at the three main strategies you can choose from:

For most websites, Strategy 1 (allow everything) or Strategy 2 (selective) works best. The right choice depends on how much you value AI search traffic versus how much you want to protect your content from AI training. If you are not sure, start with Strategy 1 and monitor your AI traffic. You can always switch to Strategy 2 later if you change your mind.

How to Set Up Your Google Crawler Rules

Setting up the right Google crawler rules in your robots.txt is easy. Follow these steps:

Common Mistakes to Avoid

Here are the most common mistakes website owners make when dealing with Google crawlers:

Impact on Your AI Visibility Score

Google-Extended is one of the Tier 1 AI bots that affect your AI Visibility Score. Allowing Google-Extended contributes to the Bot Access portion of your score (which is worth 65 points total).

Here is how your decision about Google-Extended affects your AI Visibility Score:

Remember that Google-Extended is just one of five Tier 1 bots. The others are GPTBot, ClaudeBot, PerplexityBot, and ChatGPT-User. To get the highest possible AI Visibility Score, you need to allow all five. But even if you block Google-Extended, you can still have a good score by allowing the other four.

Also, do not forget about the AI Infrastructure portion of the score. Adding an llms.txt file (20 points) and an llms-full.txt file (15 points) can make a big difference regardless of your Google-Extended decision.

Google-Extended in the Broader AI Crawler Landscape

Google-Extended is part of a much bigger picture. In 2026, there are more than 154 known AI crawlers on the web. Each major AI company has its own crawlers, and they all work differently. Here is how Google-Extended fits into the overall landscape:

When you make decisions about Google-Extended, you should also think about the other major AI training crawlers. GPTBot from OpenAI collects data for ChatGPT. ClaudeBot from Anthropic collects data for Claude. PerplexityBot collects data for Perplexity. Your strategy should be consistent across all of these bots, or at least consider each one individually.

Many website owners choose to treat all AI training crawlers the same way: either allow all of them for maximum visibility, or block all of them for maximum content protection. But you can also make different decisions for different companies. For example, you might allow Google-Extended (because you value AI Overviews visibility) while blocking GPTBot (because you do not want your content in ChatGPT training data).

The key is to have a clear strategy that matches your business goals. Our robots.txt best practices guide covers strategies for all types of websites. And our AI crawler blocking guide shows you exactly how to implement your chosen strategy.

Beyond robots.txt, you should also consider creating an llms.txt file. This file tells AI systems what your website is about and which pages are most important. It works together with robots.txt to give you the best possible AI visibility. Adding llms.txt can boost your AI Visibility Score by up to 35 points.

The world of AI crawlers is changing fast. New bots appear every few months, and existing bots add new features. We recommend checking your AI crawler status at least once a quarter using AI Crawler Check. This way, you can stay on top of changes and make sure your strategy is still working.

Summary

Understanding the difference between Googlebot and Google-Extended is essential for every website owner in 2026. Making the wrong choice can either cost you Google Search traffic (if you block Googlebot) or cost you AI visibility (if you block Google-Extended without thinking it through). Here are the key points: