Verifying Googlebot and other Google crawlers

You can verify if a web crawler accessing your server really is a Google crawler, such as Googlebot. This is useful if you're concerned that spammers or other troublemakers are accessing your site while claiming to be Googlebot.

Google's crawlers fall into three categories:

Type Description Reverse DNS mask IP ranges
Common crawlers The common crawlers used for Google's products (such as Googlebot). They always respect robots.txt rules for automatic crawls. crawl-***-***-***-***.googlebot.com or geo-crawl-***-***-***-***.geo.googlebot.com googlebot.json
Special-case crawlers Crawlers that perform specific functions for Google products (such as AdsBot) where there's an agreement between the crawled site and the product about the crawl process. These crawlers may or may not respect robots.txt rules. rate-limited-proxy-***-***-***-***.google.com special-crawlers.json
User-triggered fetchers Tools and product functions where the end user triggers a fetch. For example, Google Site Verifier acts on the request of a user. Because the fetch was requested by a user, these fetchers ignore robots.txt rules.
Fetchers controlled by Google originate from IPs in the user-triggered-fetchers-google.json object and resolve to a google.com hostname. IPs in the user-triggered-fetchers.json object resolve to gae.googleusercontent.com hostnames. These IPs are used, for example, if a site running on Google Cloud (GCP) has a feature that requires fetching external RSS feeds on the request of the user of that site. 		***-***-***-***.gae.googleusercontent.com or google-proxy-***-***-***-***.google.com user-triggered-fetchers.json and user-triggered-fetchers-google.json

There are two methods for verifying Google's crawlers:

  • Manually: For one-off lookups, use command line tools. This method is sufficient for most use cases.
  • Automatically: For large scale lookups, use an automatic solution to match a crawler's IP address against the list of published Googlebot IP addresses.

Use command line tools

  1. Run a reverse DNS lookup on the accessing IP address from your logs, using the host command.
  2. Verify that the domain name is either googlebot.com, google.com, or googleusercontent.com.
  3. Run a forward DNS lookup on the domain name retrieved in step 1 using the host command on the retrieved domain name.
  4. Verify that it's the same as the original accessing IP address from your logs.

Example 1:

host 66.249.66.1
1.66.249.66.in-addr.arpa domain name pointer crawl-66-249-66-1.googlebot.com.

host crawl-66-249-66-1.googlebot.com
crawl-66-249-66-1.googlebot.com has address 66.249.66.1

Example 2:

host 35.247.243.240
240.243.247.35.in-addr.arpa domain name pointer geo-crawl-35-247-243-240.geo.googlebot.com.

host geo-crawl-35-247-243-240.geo.googlebot.com
geo-crawl-35-247-243-240.geo.googlebot.com has address 35.247.243.240

Example 3:

host 66.249.90.77
77.90.249.66.in-addr.arpa domain name pointer rate-limited-proxy-66-249-90-77.google.com.

host rate-limited-proxy-66-249-90-77.google.com
rate-limited-proxy-66-249-90-77.google.com has address 66.249.90.77

Use automatic solutions

Alternatively, you can identify Googlebot by IP address by matching the crawler's IP address to the lists of Google crawlers' and fetchers' IP ranges:

For other Google IP addresses from where your site may be accessed (for example, Apps Scripts), match the accessing IP address against the general list of Google IP addresses. Note that the IP addresses in the JSON files are represented in CIDR format.