Google Confirms It Uses Hundreds Of Undocumented Crawlers
Google has revealed that its web crawling system is far more complex than many SEO professionals realize. According to statements from Gary Illyes, the company operates hundreds of crawlers that are not publicly documented, highlighting the scale of Google’s infrastructure and the many teams that rely on it.
The disclosure offers rare insight into how Google retrieves content from across the internet and how different products within the company rely on a shared crawling framework.
Googlebot Isn’t Just One Crawler
For many years, website owners have used the term Googlebot to describe the system that visits websites and gathers information for Google Search. However, the reality is far more complex.
Illyes explained that Googlebot originally referred to a single crawler in the early days of Google, when the company had only one main product. As Google expanded into multiple services – such as ads, search features, and other platforms – additional crawlers were created.
Today, the name “Googlebot” is mostly a historical label. Instead of one crawler, Google operates a large ecosystem of crawlers that interact with a shared internal crawling infrastructure.
Google’s Internal Crawling Infrastructure
According to Gary Illyes, the crawling system functions similarly to a software-as-a-service platform used internally by Google teams. Developers can send requests to this system to fetch web pages from the internet.
This infrastructure then retrieves the requested page while ensuring that websites are not overloaded with requests. In simple terms, the system allows internal Google teams to fetch content from the web safely and efficiently.
Why Many Crawlers are Not Documented?
One of the most surprising revelations is that many Google crawlers are not publicly listed.
Illyes explained that multiple teams inside Google rely on the crawling infrastructure for different products and experiments. As a result, there could be dozens or even hundreds of individual crawlers operating simultaneously
If a crawler begins fetching a large number of URLs, Google may review it and eventually add documentation for transparency.
Crawlers vs. Fetchers: What’s The Difference?
Crawlers
Fetchers
Fetchers are typically tied to user-initiated processes, while crawlers run continuously in the background to discover and index web content.
What This Means For SEO Professionals?
Recent updates such as the Google February 2026 Core Update insights show how Google continues to evolve its search infrastructure.
Key Takeaways
Technical SEO, crawl optimization, and authority signals remain crucial – something highlighted in this link building agency checklist.
