Google explains the use cases for its different crawler types

Google has now added new particulars that designate the three classes its Google crawlers fall into, they embody Googlebot, special-case crawlers and user-triggered fetchers.

As well as, Google now lists a JSON formatted file containing the listing of IP addresses every of those totally different crawler sorts use.

Sorts of Google crawlers. On the prime of this Googlebot page, Google listed these three crawler sorts:

• Googlebot – The primary crawler for Google’s search merchandise. Google says this crawler all the time respects robots.txt guidelines.
• Particular-case crawlers – Crawlers that carry out particular features (akin to AdsBot), which can or might not respect robots.txt guidelines.
• Consumer-triggered fetchers – Instruments and product features the place the end-user triggers a fetch. For instance, Google Web site Verifier acts on the request of a consumer or some Google Search Console instruments will ship Google to fetch the web page based mostly on an motion a consumer takes.

IP addresses. Google additionally listed the IP deal with ranges and reverse DNS masks for every kind:

What’s new. Right here is the part of the web page that was up to date; the remainder of the web page is usually unchanged.

Why we care. I consider Google made this variation after they noticed a few of the reactions to the GoogleOther robot they introduced the opposite day. This now explains how Google crawlers act, once they respect the robots.txt and methods to determine them higher.

Now, if you need to not block Google’s fundamental crawler, Googlebot, however you resolve to dam the others, you may higher determine these crawlers extra precisely.