Ads keep Google and most of the websites and services you use free of charge. We go to great lengths to make sure ads are safe, unobtrusive and as relevant as possible. For example, you will not see pop-up ads on Google, and every year we terminate the accounts of hundreds of thousands of publishers and advertisers who violate our policies (including advertisements containing malware, advertisements for fake products, or ads that try to abuse your personal information).

How does Google use cookies in advertising services?

Cookies help advertising be more effective. Without cookies, it becomes difficult for an advertiser to reach their audience or know how many ads were shown and how many times they were clicked.

Many websites, such as news sites and blogs, partner with Google to show ads to their visitors. Working with our partners, we may use cookies for a variety of purposes, such as preventing you from seeing the same ad over and over, stopping click fraud, and showing more relevant ads (for example, displaying ads based on the websites you visit).

We keep a record of the ads we serve in our logs. These server logs typically contain your web request, your IP address, your browser type, your browser language, the date and time of your request, and one or more cookies that can uniquely identify your browser. There are many reasons why we store this data. Among the most important reasons are to improve our services and to ensure the security of our systems. We anonymize this data by removing part of the IP address (after 9 months) and cookie information (after 18 months).

Our advertising cookies

We offer many products to help our partners manage their own ads and websites, including AdSense, AdWords, Google Analytics and a variety of DoubleClick branded services. When you visit a page using one of these products on Google services or other sites and applications, or when you see an advertisement, various cookies may be sent to your browser.

These may be set from several different domains, including,,, or, or the domains of our partners’ sites. Some of our advertising products allow our business partners to use other services in conjunction with our services (ad measurement, reporting service, etc.), and these services may send their own cookies to your browser. These cookies are set from their domain names.

Find out more about the types of cookies used by our partners and Google , and how we use them .

How can you control advertising cookies?

You can use Ad Settings to manage the Google ads you will see and disable Ads Personalization . Even if you disable Ads Personalization, you may still see ads based on factors such as your general location determined by your IP address, your browser type, and your search terms.

You can also manage cookies used by many companies for online advertising with consumer selection tools created under automated control programs in most countries. For example , tools such as the US-based options page or the EU-based Your Online Choices are available.

Finally, you can manage cookies in your Web browser .

Other technologies used in advertising

Google’s advertising systems may also use other technologies such as Flash and HTML5 for functions such as displaying interactive ad formats. For example, we may use your IP address to determine your general location . You can view ads on your device model, browser type, or accelerometer on your device. We may also select based on information about your computer or device, such as sensors.


Google’s advertising products can find out or predict your location with information from a wide variety of sources. For example, we may use your IP address to determine your general location; we can get your exact location from your mobile device; We can estimate your location based on your search queries, and the websites and apps you use can send us information about your location. Google uses location information in our advertising products to improve the relevance of the ads it displays to you, to obtain demographic information, to measure ad performance, and to provide aggregated statistics to advertisers.

Advertising identifiers for mobile applications

We may use technologies that perform similar functions to cookies to serve ads in services (for example, mobile applications) where cookie technology cannot be used. Sometimes Google binds the identifier used for advertising in mobile applications to an advertising cookie on the same device in order to manage ads in your mobile applications and mobile browser. For example, this can be done when you see an ad that opens a web page on your mobile browser while using an app. This use also helps us improve the reports we provide to our advertisers on the efficiency of their campaigns.

To disable personalized ads in apps on your mobile device, follow the instructions below.


  1. You can find Google Settings in one of the following places (depending on your device):
    1. A separate application called Google Settings
    2. In your main Settings app, scroll down and tap Google
  2. Tap Ads
  3. Enable the opt out of interest-based ads option


iOS devices use Apple’s Advertising Identifier. To learn more about your options for using this identifier, visit the Settings app on your device .

When I see an ad served by Google, what determines which ad is served?

While determining which ad to see, many decisions are made.

Sometimes the ad you see is based on your current or past location. Your IP address is usually a good indicator of approximating your location. That way, you may see an ad on the home page of promoting an upcoming movie in your country, or when you search for “pizza,” the search results can list pizzerias in your city.

Sometimes the ad you see is based on the content of a page. If you’re browsing a site with gardening tips, you may see ads for gardening tools.

Sometimes you may see an ad based on your app activities or activities on Google services on the web, an in-app ad based on your web activity, or an ad based on your activities on another device.

Sometimes the ad you see on a page is served by Google, but another company chooses the ad. For example, you may have registered on a newspaper’s website. Based on the information you provide to the newspaper, the website can make decisions about which ads to show you and use Google’s ad serving products to serve relevant ads.

You may also see ads for Google products and services such as Search, Gmail, and YouTube based on information you give to advertisers, such as your email address that they also share with Google.

Why am I seeing ads served by Google for products I’ve previously viewed?

You may see ads for products you have viewed before. For example, suppose you visit a website that sells golf clubs, but you did not purchase any golf clubs from the site on your first visit. The owner of the website may want to encourage you to come back to the site and complete the purchase. Google offers services that allow website operators to target their ads to users who have visited their pages.

For this to work, Google either reads a cookie already in your browser or places a cookie in your browser when you visit the golf site (assuming your browser allows this).

When you visit another site that works with Google, you may see an ad for golf clubs that you were interested in before, even if the content of the site is not golf-related. This is because your browser sends the same cookie to Google. Thus, we may use this cookie to serve an advertisement that encourages you to purchase the relevant golf clubs.

Your visit to the golf site may also be used by Google to show you tailored advertisements when you later search for golf clubs on Google.

We have restrictions for these types of ads. For example, we prohibit advertisers from selecting target audiences based on sensitive information such as health information or religious beliefs.

Learn more about Google ads .