We are updating the referer of ad clicks to improve security and system reliability for users searching on Google. Starting within October, the referer for many ad clicks will only contain the Google domain from which the click occurred (domains like https://www.google.com or https://www.google.ca). This means that we will no longer be communicating specific paths such as “google.com/aclk” or “googleadservices.com/pagead/aclk.”

While the referer will no longer differentiate Google’s organic search clicks from ad clicks, and in some cases may be absent entirely, there are still multiple strategies to track the origin of your clicks. Recommended strategies include: This change is a continuation of our general user security efforts. Users are safer when sites use HTTPS instead of HTTP, which is why we encourage the use of HTTPS. In fact, in August 2014 we began to use HTTPS as a ranking signal.

By default, browsers do not pass a referer from HTTPS sites to HTTP sites. To minimize advertiser disruption, we implemented a custom ads solution back when the Google search page migration to HTTPS took place. Now, many modern web browsers provide better control over referer behavior via the meta referer tag. This development is an improvement over our previously-implemented custom ads solution both in terms of reliability and latency.