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Device-Identified Information (DII) is any data that is linked to a particular browser or device if that data is not used, or intended to be used, to directly identify a particular individual. Used for Tailored Advertising by NAI member companies, this data consists primarily of click-stream information (sites you have visited or links you have clicked) that, when using HTTP Cookies, is tied to a randomly generated anonymous identifier.

As a general rule, Tailored Advertising does not depend on information that personally identifies you, such as your name, e-mail address, phone number, photographs, etc. Rather than using Personally Identified Information, most Tailored Advertising uses randomly-generated numbers to match your web browser or mobile device with interest categories. In some cases, Personally Identified Information is used to bring interest categories online, but NAI member companies take measures to keep Personally Identified Information separate from online browsing activities.

Interest-Based Advertising uses information collected across multiple websites to predict your preferences or infer your interests and to show you ads that are more likely to be of interest to you. MORE ›

Personally Identified Information (PII) includes name, address, telephone number, email address, financial account number, non-publicly available government-issued identifier, and any other data that is linked, or intended to be linked to  contact, or precisely locate a person. The NAI Codes provide disincentives to the use of PII for Tailored Advertising. As a result, NAI member companies generally use only information that is not PII for Tailored Advertising and do not merge the DII they collect for Tailored Advertising with users’ PII.

Many of the banner ads displayed on web pages are not selected and delivered by the websites you visit, but by network advertising companies that manage and provide advertising for numerous unrelated websites. These companies, which we refer to as “third-party ad networks,” or “third-party ad companies,” join the NAI to signal their adherence to privacy best practices and to provide a means for consumers to opt out of Targeted Advertising on the NAI website.

The term “third-party” indicates that rather than having a direct relationship with a user, a company has a relationship with one or more of the websites that a user visits. For example, if a user visits, that website is the “first party.” If partners with an advertising network, platform, or exchange to place ads, the network, platform, or exchange is the “third party.” The advertising network uses cookies when the user visits to help it select and serve the best ad. These cookies are considered “third-party cookies.” First parties partner with third parties in this way because third parties have technology and expertise to enable more efficient ad placement across websites. NAI members, working with brands, publishers and websites, use third-party cookies to make advertising more engaging and relevant to users and more valuable to publishers and advertisers.

An example of a non-cookie technology is a statistical (or probabilistic) identifier. Such an identifier is the result of a computation about a browser or device that companies rely on to tailor their online advertising. Instead of placing a cookie on a browser, and then reusing the value inside of the cookie to identify the browser, companies hope to identify a browser or device by using data about the browser or device to compute a value. Non-cookie technologies operate differently and could be used for a variety of purposes. These could include ensuring your online banking stays secure, preventing online shopping fraud, or serving you the right online advertisements.

Most modern mobile devices (iOS 6, Android 2.3, and Windows 10 and above) provide mobile advertising identifiers. These are randomly-generated numbers that are associated with your device that often come with options to reset the identifier and opt-out of Cross-App Advertising. These identifiers have different names depending on the operating system. For example, they are called Google Advertising ID (GAID) on Android devices whereas on iOS, they are called Identifiers for Advertisers (IDFA). They are included to provide advertisers a method to identify your devices without using a permanent device identifier, like your phone’s serial number.

Many of the banner ads displayed on web pages and applications are not selected and delivered by the websites or apps you visit, but by third-party advertising companies that manage and provide advertising for numerous unrelated websites and applications. Websites and applications work with third-party advertising companies because these companies can more efficiently sell advertising space. This enables websites and applications to make more revenue and continue providing free content and services. Some of these companies, which we refer to as “third-party ad companies,” join NAI to signal their commitment to privacy best practices and in some occasions to provide a means for consumers to opt out of Tailored Advertising on the NAI website or via mobile platform settings or smart TV and streaming device settings.

The short answer – a Web beacon enables two websites to share information. Generally, a web beacon consists of a small piece of software code, just like the other code that makes up a web page, that incorporates a graphic image on a web page or email. There may or may not be a visible graphic image associated with the web beacon, and often the image is designed to blend into the background of a web page or email. Web beacons can be used for many purposes — including site traffic reporting, unique visitor counts, advertising auditing and reporting, and personalization.

If you encounter technical difficulties while trying to opt out, we ask that you first try again.

If you continue to experience problems, please visit our support page.

Yes. Opting out of Interest-Based Advertising by one or more NAI member company using the NAI opt-out tool stops those companies from engaging in Interest-Based Advertising for your browser. You will still see ads, some of which may be delivered by NAI member companies. However, because the NAI member companies from which you have opted out will no longer use Interest-Based Advertising data to target those ads to your computer, the ads may be less relevant.

Consumers have a variety of options available to customize their web and app experience ranging from browser controls and add-on utilities to opt-out tools. Learn more about those options.

The NAI opt-out tool automatically scans your browser to look for Interest-Based Advertising cookies set by each of our member companies. Simply go to the opt-out page to check your browser.

Your browser must be set to accept third-party cookies in order for the NAI opt-out tool to work. Settings that limit the duration of cookies, such as private browsing mode or browser options that treat all cookies as session cookies, will limit how long your opt-out will last.

Attention Safari users: Apple presets the Safari browser to block cookies from sites other than those you visit directly. As a result, the NAI opt-out tool, which uses third-party cookies, generally will not work on browsers left in this default setting. If you are using Safari and wish to use the NAI’s opt-out tool, you can change your cookie settings to allow all cookies and then use the NAI opt-out tool. Opt-out cookies for the selected NAI member companies can then be placed on your computer or device. You can change your cookie settings back after completing this action, if desired.
Having problems?

Attention Internet Explorer users: Yahoo! has a security path that allows Internet Explorer to block its ad network (third-party) cookies when a user’s browser privacy setting is set to “Medium High” or “High.” As a result, the NAI opt-out tool, which uses third-party cookies, cannot place Yahoo!’s opt-out cookie for browsers that use this setting at this time. For more information on changing your IE browser settings click here.
Having problems?

Not necessarily. Some NAI members offer services that are unrelated to Interest-Based Advertising, and others place cookies on your browser for purposes such as ad delivery and reporting, such as fraud prevention, and limiting the number of times you see an ad. Opt-out cookies signal to NAI member companies not to tailor ads based on information collected across websites, but they may leave the cookies used for other purposes in place.

The NAI opt-out tool reports which NAI member companies have placed a cookie on your browser that can be used for Interest-Based Advertising on your browser by checking for the presence of such cookies and reporting back whether it found any “active” cookies. The NAI opt-out tool also allows you to set cookies that will tell NAI members you do not want to participate in Interest-Based Advertising. The tool does not delete all cookies on your browser nor does it necessarily replace other cookies delivered by NAI companies, such as those that are used for ad reporting or ad serving purposes that, for example, allow advertisers to change the sequence of ads, as well as to track the number of ads delivered. Also, the opt-out tool affects only the browser that is used. On mobile devices, for example, it would apply to the particular browser that was used to visit NAI’s opt-out page, and not cross-app advertising or interest-based advertising on a different browser. If you use private browsing mode or switch users in your browser, you will likely need to revisit the NAI opt-out page since the cookies on your browser will have been removed or modified.

Please Note:  Technology used to deliver interest-based advertising continues to evolve and change.  As of the date of publication of this page, this opt out covers Interest-Based Advertising delivered to your browser via HTTP cookies only.  It does not cover the use of other technologies on your browser that NAI member companies may use to deliver interest-based advertising. NAI and its members are currently working on developing a mechanism to allow you to opt out of the use of non-cookie technologies for Interest-Based Advertising by NAI members. NAI is working with its members during an implementation period to ensure that new business models and non-cookie based technologies are implemented by NAI members in a manner that is consistent with the Guidance on the Use of Non-Cookie Technologies for Interest-Based Advertising.


The NAI opt-out tool covers only member companies’ use of cookies to target advertising based on users’ web browsing.

We do not maintain opt-out programs for postal or electronic mail, text messages, or for pop-ups.
For more information about controlling spam and email preferences visit the FTC website.

The NAI opt-out page will set opt-out cookies for the browser you used to access the webpage. This does not cover the Cross-App Advertising that you normally see across your apps. To opt-out of such types of advertising, please see the settings on your mobile device.

NAI members and the online advertising industry as a whole have also pledged not to use information gathered for Tailored Advertising to decide if you’re eligible for employment, health insurance, or credit.

Our goal is to share information about some common ways that NAI members engage in tailored advertising. Through brief, easy-to-read summaries and simple diagrams, we hope to teach consumers how tailored advertising generally works when a user visits a website and how Cross-App Advertising works when a user visits an app. We don’t cover every variation in business practices, and given how rapidly technologies change, we can’t promise that the site will always reflect the latest techniques used for tailored advertising.

No. Cookies are not software, and cannot run as programs on your computer. Cookies cannot read or examine the data on your computer or alter its settings in any way. Still, you should always take precautions to ensure your devices are protected. More information about computer security.