- 1 Definition
- 2 How do tracking pixels work?
- 3 What are tracking pixels used for?
- 4 Integration of a tracking pixel into HTML code
- 5 What is the difference between tracking pixels and cookies?
- 6 Advantages and criticism of the use of tracking pixels
- 7 How can users protect themselves from tracking pixels?
- 8 Related links
How do tracking pixels work?
The very small size of a tracking pixel is an essential part of its functionality. Tracking pixels are intentionally hidden in the background of a web page or email so that they are not part of the user experience. The intention behind this is to enable a back-end process that does not distract from the content of a website or marketing email.
Tracking pixels are embedded in the HTML code of a website, online ad or marketing email and are retrieved from the server every time a user loads that website, ad or email into their web browser. The server then sends the pixel tag to the user's unique IP address and logs it. The server thus counts the number of retrievals.
What are tracking pixels used for?
Tracking unique page-views is the most basic function of a tracking pixel. Web site operators, email marketers or advertisers who use a tracking pixel can analyze the server logs and see how many unique page-views their content has received. For example, if 10,000 unique IP addresses have accessed a tracking pixel, this means that 10,000 different users have seen the content of the website, ad or marketing email.
The traffic data collected with a tracking pixel can then be further analyzed, e.g. for marketing purposes. More accurate analysis of IP addresses can provide a basic idea of where users come from geographically and what type of devices and operating systems they use to visit a website. IP addresses can also be tracked as users move across a website or click various links or ads hosted on the same server. This gives website owners and advertisers a clearer picture of what users are looking for and why they are visiting the site. This data can be used to tailor content and ads to users' needs through targeted marketing campaigns.
Integration of a tracking pixel into HTML code
Tracking pixels can be integrated into the source code of a website as follows:
<img src="URL tracking pixel" width="0" height="0">
<img src="URL tracking pixel" style="position:absolute; visibility:hidden">
<img src="URL tracking pixel" style="display:none">
When a visitor accesses a site, the tracking pixel is loaded from the server using the <img> tag. "URL tracking pixel" indicates the location of the image on the server. The style attributes "visibility:hidden" and "display:none" specify that the image is hidden or not displayed. Alternatively, as in the first example, the values for width and height of the image can be set to "0" to prevent the tracking pixel from being displayed.
Advantages and criticism of the use of tracking pixels
The advantage of tracking pixels for advertisers and website owners lies in the simple implementation of tracking pixels in websites, emails, and advertisements.
However, tracking pixels are often criticized with regard to data security aspects. Although collecting data about user behavior can be extremely helpful for marketing campaigns, the information is usually collected and transmitted without the knowledge or consent of users. In this respect, the privacy of users is violated by recording their behavior. In addition, it is easy to use the IP address to combine the collected information with other information and user profiles from social media, for example.
Another point of criticism is that pixel tags are often used in spam emails to check whether an email has been sent to a valid email address. When users open the spam email, the image is loaded and the address is recognized as valid. Subsequently, more unwanted emails are sent to this address.
How can users protect themselves from tracking pixels?
For a long time, tracking pixels could not be detected and blocked by browsers. Today, however, users can use plug-ins for their browser or special programs to make tracking pixels visible, block them and prevent the analysis of log files. Proxy servers or the Tor browser also prevent the download of tracking pixels and an entry in server log files. Users can also adjust their browser settings so that images are only loaded and displayed with their permission. In email programs, it is also possible to switch off support for HTML format emails so that HTML emails are not displayed and the downloading of a tracking pixel is thus prevented.