Types of cookies used by Google

We use different types of cookie to run Google websites. Some or all of the cookies identified below may be stored in your browser. You can view and manage cookies in your browser (though browsers for mobile devices may not offer this visibility).

Category of use Example

Preferences

These cookies allow our websites to remember information that changes the way the site behaves or looks, such as your preferred language or the region you are in. For instance, by remembering your region, a website may be able to provide you with local weather reports or traffic news. These cookies can also assist you in changing text size, font and other parts of web pages that you can personalize.

Loss of the information stored in a preference cookie may make the website experience less functional but should not prevent it from working.

Most Google users will have a preferences cookie called ‘PREF’ in their browsers. A browser sends this cookie with requests to Google’s sites. The PREF cookie may store your preferences and other information, in particular your preferred language (e.g. English), how many search results you wish to have shown per page (e.g. 10 or 20), and whether or not you wish to have Google’s SafeSearch filter turned on.

Security

We use security cookies to authenticate users, prevent fraudulent use of login credentials, and protect user data from unauthorized parties.

For example, we use cookies called ‘SID’ and ‘HSID’ which contain digitally signed and encrypted records of a user’s Google account ID and most recent sign-in time. The combination of these two cookies allows us to block many types of attack, such as attempts to steal the content of forms that you complete on web pages.

Processes

Process cookies help make the website work and deliver services that the website visitor expects, like navigating around web pages or accessing secure areas of the website. Without these cookies, the website cannot function properly.

For example, we use a cookie called ‘lbcs’ which makes it possible for Google Docs to open many Docs in one browser. Blocking this cookie would prevent Google Docs from operating correctly.

Advertising

We use cookies to make advertising more engaging to users and more valuable to publishers and advertisers. Some common applications of cookies are to select advertising based on what’s relevant to a user; to improve reporting on campaign performance; and to avoid showing ads the user has already seen.

Google uses cookies, like the PREF cookie, to help personalize ads on Google properties, like Google Search, particularly when you aren’t signed in to a Google account. We also use cookies for advertising we serve outside of Google. Our main advertising cookie is called ‘id’ and it is stored in browsers under the domain doubleclick.net. We use others with names such as _drt_, FLC, NID and exchange_uid.

Sometimes a cookie may be set on the domain of the site you are visiting. In the case of our DoubleClick product, a cookie called ‘__gads’ may be set on the domain of the site you are visiting.

Other Google properties like YouTube, may also use the Doubeclick cookie to personalize ads. Find out more about ads and Youtube.

Google also uses a conversion cookie to help advertisers determine how many people who click on their ads end up purchasing their products. These cookies allow Google and the advertiser to tell that you clicked the ad and proceeded to the advertiser site. They do not link your browsing between advertiser sites and they persist for a limited time. These cookies are set in the googleadservices.com domain.

Some of our advertising products allow other companies to send their own cookies to your browser. For example, when you visit a page that uses DoubleClick, you may find that cookies are sent to your browser by Google and also by other parties. Each publisher and advertiser may work with various technology and service providers and each of these parties may set its own cookies, though each cookie can only be read by the domain that sets it. This means that several cookies may be sent to your browser by several companies in the time it takes a single web page to load. This is how most online advertising works.

Session State

Websites often collect information about how users interact with a website. This may include the pages users visit most often, and whether users get error messages from certain pages. We use these so-called ‘session state cookies’ to help us improve our services, in order to improve our users’ browsing experience. Blocking or deleting these cookies will not render the website unusable.

These cookies may also be used to anonymously measure the effectiveness of PPC (pay per click) and affiliate advertising.

For example, we use a cookie called ‘recently_watched_video_id_list’ so that YouTube can record the videos most recently watched by a particular browser.

Analytics

Google Analytics is Google’s free web analytics tool that mainly helps website owners to understand how their visitors engage with their website. It also sets cookies on the domain of the site you are visiting. It uses a set of cookies with names like ‘__utma’ and ‘__utmz’ to collect information anonymously and report website trends without identifying individual visitors. Learn more about Analytics cookies and privacy information.