What is invalid traffic?

Invalid traffic is any activity that doesn't come from a real user with genuine interest. It can include accidental clicks caused by intrusive ad implementations, fraudulent clicking by competing advertisers, advertising botnets and more.

Our Ad Traffic Quality team is dedicated to stopping all types of invalid traffic so that advertisers don't have to pay for it and the people who cause it don't profit from it. We also work closely with industry groups like the Interactive Advertising BureauMedia Rating CouncilTrustworthy Accountability Group, among others to develop industry standards for advertising traffic worldwide.

Below, we will describe a few examples of invalid traffic. Please note that this is not an exhaustive list.

  • Invalid user activity

    Invalid user activity is when a real person interacts with an ad, but not out of actual interest.

    Some actions are accidental, like when a mobile user reaches for a link and taps an ad instead. Others are intentional and sometimes downright fraudulent. For example, publishers might ask (or even pay) users to click on ads, watch videos, or view content they wouldn't normally engage with to increase their impression counts.

    Traffic caused by deceptive tactics like these creates bad user experiences and provides little or no value to advertisers, which is why we are committed to stamping it out.

  • Accidental Clicks

    Accidental Clicks

    Accidental clicks happen, as the name implies, when users didn't intend to click on an ad. They often occur as a result of poor ad placement. For example, ads should be clearly distinguished from other website content, such as menu, navigation, and download links. Please review our Ad placement policies to learn more.

  • Ad Hiding

    Ad Hiding

    Ad hiding is when ads are placed in ways that make them impossible to see under any normal circumstances. Some examples are ads tucked under iframes, hidden behind content, hidden behind other ads, inside invisible HTML containers, or ads that are displayed but too small to be seen (aka "pixel stuffing").

  • Ad Injection

    Ad Injection

    Ad injections happen when ads are inserted into pages without the publisher’s knowledge and are often created by free wifi applications, browser plugins, and 'software bundles.' Ad injectors provide a poor user experience and potentially cause privacy leaks. This type of attack also steals revenue from publishers.

  • Ad Stacking

    Ad Stacking

    Ad stacking is when multiple ads are stacked in layers in a single ad space, and only the top ad shows. An advertiser is led to believe that their ad was shown on a web page (or inside an app), when in fact it was rendered but not actually seen (because it's hidden by the top ad).

  • Botnets


    Botnets are automated software programs that run on Internet servers or hijacked computers. When used for ad fraud, botnets can be programmed to create a large volume of invalid impressions, clicks, and traffic. Unfortunately, they can also be programed to act like real users, which makes their traffic difficult to spot. So in addition to our automated filters and manual reviews, we also deploy specialized research teams to hunt out and stop botnets harming advertisers, publishers and users.

  • Clickjacking


    Clickjacking is the use of deceptive elements (e.g., buttons) or interfaces on a web page in a way that a user is tricked into clicking on an ad that they didn't expect to click on. These types of attacks are usually implemented by overlaying an invisible ad unit over a web page element or using code that allows an invisible ad unit to follow the user's cursor.

  • Falsely Represented Inventory

    Falsely Represented Inventory

    Falsely represented inventory is based on ad traffic falsely portrayed as coming from high-value users or a site claiming it is a different site.

  • Misrepresentation of in-stream and out-stream video

    Misrepresentation of in-stream and out-stream video

    In-stream video typically represents pre-, mid-, or post-roll ads shown within other video content (essentially these ads are blended into the primary video content). In-stream video can generate invalid traffic when it is primarily based on non-human traffic to videos, in which an in-stream video ad is marked or measured incorrectly as having been viewed by a real user.

    Misrepresentation of out-stream video

    Out-stream video is what is typically shown in "display" ads such as banners, interstitials, native (inline) ads, etc (in contrast to in-stream video, which is blended with other video streams). Out-stream video invalid traffic is the misrepresentation and display of in-stream video in an out-stream format. For example, this happens when in-stream video ads are shown in a banner ad -- an advertiser is led to believe that their ad was displayed in-stream with other video content, when in fact it was displayed in a different format.

  • Malware


    Malware is any kind of software that's designed to harm a computer. Malware can infect mobile devices to generate various types of fraudulent traffic. This traffic can include hidden ads served in the background (without the user's knowledge) and interstitial ads injected and displayed over a user interface.

  • Pop-under ad

    Pop-under ad

    Pop-under ads are ads that are displayed in a new browser window that are typically opened under (behind) the active browser window. As a result, the user is unaware that the pop-under ad has been displayed until the active window, or windows are closed. Often this leads to a bad user experience, especially so because it's difficult to determine which web site led to a pop-under ad.

  • Industry collaboration is essential in the fight against invalid activity

    We work hard to keep our own networks free from invalid traffic, but to prevent invalid activity across the web we all need to work together. We believe that industry collaboration is an essential element of the fight against invalid traffic, which is why we collaborate both formally and informally on relevant efforts across the industry. We engage in and participate in key working groups in the IAB Tech Lab and the Trustworthy Accountability Group (TAG), and we also participate in accreditation of our invalid traffic defenses by the Media Rating Council (MRC). In addition to working with these industry bodies, we also collaborate with other organizations through more informal efforts that are mutually beneficial. One example of this more informal collaboration is the takedown of the 3ve ad fraud operation, which entailed collaboration between Google and various other players in the digital advertising ecosystem.