Google Checks 4 Billion Host Names Each Day For Robots.txt

What? 4 billion daily scans!! That’s incredible.

In a recent revelation on the SOTR Podcast, Google’s Gary Illyes disclosed that the search
engine giant daily crawls an astounding 4 billion hostnames for robots.txt.

For those that are new to the web, let make it clear that the robots.txt file serves as a set of
guidelines provided by website administrators to instruct web crawlers about which pages or
sections of their site should be crawled and indexed and which ones should be excluded.

It’s essential.

Reduced control over the website, increased resource usage, and legal and ethical issues are
very likely if Google stops doing this. But certainly, this isn’t an easy job.

During the " Search Off the Record" podcast, Gary Illyes explained the magnitude of the
challenge behind the scene, stating,

If you go through our robots.txt cache, you can see that we have about four billion host
names that we check every single day for robots.txt.

And this is quite astonishing. However, the actual number of websites is likely even higher,
surpassing the four billion mark, if not now, then definitely in the future.

But this implies that Google is dealing with an enormous number of websites and
subdomains.

During the discussion, Illyes and his colleagues even acknowledged the frustration among
publishers regarding the absence of an opt-out mechanism.

For example, most larger websites with a limited number of server resources want to manage
crawlers access to put less strain on server capacity.

But on it, the analyst on the Google Search team questioned.

If you have four billion hostnames plus a bunch more in subdirectories, then how do you
implement something that will not make them go bankrupt when they want to implement
some opt-out mechanism?”

The conversation also touched on the challenges Google faces in managing the data within its
Search Console.

As Google continues to struggle with the massive scale of its daily checks, the tech giant
remains committed to finding the best solutions.