When you anonymize visitor IP, the last three digits from your website visitor's IP address are automatically dropped/deleted. In other words, the IP anonymization feature sets the last octet of IPv4 user IP addresses and the last 80 bits of IPv6 addresses to zeros. For example, if a website visitor has a public IP of 12.214.31.144 then as soon as the IP data is received by the Analytics Collection Network, Google will anonymize/mask the IP to 12.214.31.0 It is important to remember that IP anonymization occurs before any data storage or processing takes place. So Google does not store or process complete IP addresses at any given time.