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Tracking Pixel

A "Tracking pixel", also known as 1 × 1 pixel or pixel tag, is a graphic that is downloaded when a user visits a web portal or opens an email and used to monitor specific user actions. A tracking pixel can also be used to obtain statistical information for the analysis of Online Marketing, Web Analytics or Email Marketing.

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Tracking Pixel Features

A tracking pixel it is a graphic that generally has the dimensions of only 1 × 1 pixel. In this way, it is so tiny that users cannot even see it. To keep it hidden, these tracking pixels are designed in such a way that they are transparent or camouflaged with the background color of the web portal.

The tracking pixels appear within the source code as follows:

<img src="“Tracking" pixel url” style="“position:absolute;" visibility:hidden”>
<img src="“Tracking" pixel url” style="“display:none”">
<img src="“Tracking" pixel url” width="“0”" height="“0”">

The URL of the tracking pixel gives you information about where it is located on the server. Cuando el usuario visita un portal web, la imagen con la etiqueta <img> se descarga desde este servidor. Propiedades ópticas como la poca visibilidad, el camuflaje o su pequeña dimensión se establecen mediante del atributo de «estilo».


The web portal operator or the sender of an email ad adds a tracking pixel using a code in the HTML code of the web portal / email. Therefore, if a user visits the landing page, the HTML code will be processed by the user's browser. The browser will follow the link and open the graphic (invisible). This action will be saved in the server log files.

Through this pixel we can get a lot of other data about users. To obtain information about the operating systems or the type of browser, a combination with JavaScript is required.

  • Operator used (device information)
  • Browser used
  • User screen resolution
  • Time you read / visited the email / web portal
  • Actions on the web portal during the session (various tracking pixels)
  • IP address (Internet Service Provider information and location)


Tracking pixels are generally criticized as they generally collect data and information about users without their even knowing it. That is, these pixels collect information without the consent of said users since, generally, these pixels cannot even be seen in most cases. Critics focus on the fact that the use of tracking pixels breaches the regulations on user privacy. The transmission of the IP address also provides information on, for example, the profile on a social network or in a forum.

At the same time, it should be noted that tracking pixels are quite a useful tool for hackers since they make their work much easier. Spammers can embed such pixels in their emails to find out if an email address is valid or not. If the recipient opens the email and automatically downloads the tracking pixel, the spammer receives a confirmation of authenticity from the email address. Hence, spam emails increase.


Its use is very beneficial for webmasters since with these pixels, they can use information that helps them to improve your product offerings, for example, and adapt them to the tastes of its users, the most common type of browser, etc..

What's more, tracking pixels they are even more effective than the browser cache since the pixels can at the same time review the access of specific pages. On the other hand, if you also use JavaScript, you will be able to get much more information. This includes data on, for example, the screen resolution, the plugins used, the technologies that a particular browser accepts, etc.

But let's not forget that the tracking pixelit generally forms just the base. Usually other more advanced technologies are needed to get very detailed information.

The tracking pixels are also beneficial for the analysis of the sent newsletters. Through the tracking pixelswe can get very useful information about, for example, the Newsletter. Statistical data such as the "display" rate of certain emails and Newsletter posts. If at the same time we add an A / B Testing analysis we will get a good database with which to base our marketing strategies, for example.

From the user's point of view, the use of tracking pixels is also beneficial: the next Newsletter or the next email you will receive will be a lot more relevant and interesting from your personal point of view.

How to block them

Some of the possible measures to block the use of tracking pixels are:

  • Define your browser and email settings to be more restrictive. For example, blocking external graphics or HTML emails. You can also do it through the Firewall settings
  • There are extensions for the browsers with which you will be able to visualize the tracking pixels
  • Browse in anonymous mode or use proxy servers to prevent automatic download of tracking pixels
  • Disable scripts browser. Eye: this could restrict other internet functions

Importance for Web Analytics

The tracking pixels have similar characteristics to Cookies. User tracking is save through a file that sits on the user's hard drive. Despite everything, more and more users are beginning to take measures to block Cookies. Therefore, Cookies end up offering incomplete information.

The tracking pixel, in this way, is an option to Cookies since nowadays it is more likely that its use will not be blocked by a normal browser. Decidedly, there are already extensions for browsers, plugins and programs that lock tracking pixels and, in this way, the analysis of the log files.

Now we can also find tracking methods such as Canvas Fingerprinting, Event Tracking or other hybrid methods but, as in all other tracking models, they require some changes in the web portal (Eg data protection).

IMPORTANT: do not forget that now Google requires obtaining the user's authorization for the use of Cookies.

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