What Is A Tracking Pixels and How Does It Work?

If you're in the marketing space, you'll eventually come across the term, "tracking pixel."

Over the years, I've have had several campaigns that have done exceptionally well, only by direct linking.

What is a tracking pixel?

Tracking pixels allow advertisers to collect user data for web, mobile & email marketing. By installing an HTML or Javascript code snippet, marketers can track different events when the visitor acts. Marketers can use these actions to track user behavior, conversion tracking, and behavioral retargeting.

HTML Tracking Pixels

Tracking pixels are meant to load on the page, without the visitor noticing it's location and presence. They are usually placed just above the </body> to reduce the chances of a web visitor seeing the pixel. Tracking pixels are designed to be "invisible" to the visitor. Most HTML tracking pixels are images that are either hidden through CSS or are a 1x1px in dimension usually blending the same color as the website background. Recently these type of tracking pixels serves as a backup for when a visitors device doesn't support Javascript.

Example of what an HTML tracking pixel may look like:

  • <img style="position: absolute;" src="/tracking">
  • <img style="display: none;" src="/tracking">
  • <img src="/tracking" width="0" height="0">

Javascript Tracking Pixels

More often used recently are Javascript tracking pixels. Much like HTML tracking pixels, they are usually placed just above the </body> tag of a document; however, due to how browsers execute Javascript, there is no reason to hide them with CSS as the script doesn't have to be rendered in the view. Javascript tracking pixels are the preferred method because they allow marketers to track several other actions of the visitor known as event tracking. Not all devices can render or have Javascript enabled; however, so it's always a good idea to still use an HTML tracking pixel as a backup option.

Example of what a Javascript tracking pixel may look like:

  • <script type="text/javascript" src="tracking.js"></script>

Javascript Tracking Pixel From Google Ads

How Tracking Pixels Work

After the tracking pixel code snippet is added to the HTML code of a website or email, the pixel will begin to track various information about the visitor viewing the document. This user data is collected when the tracking pixel is loaded via the visitor's browser. Once the tracking pixel is processed in the browser, it is known as the pixel "firing," which means the visitor's data was sent to the pixel server collecting the information.

Common data a tracking pixel acquires. When a visitor loads a website or email, information is passed from the user agent. A user agent has information about the visitor that can be valuable to marketers, such as:

  • IP Address (used for location and Internet Service Provider (ISP) information
  • Browser (Chrome, Firefox, etc.)
  • Device Type (Mobile, Desktop, Tablet)
  • Operating System (iOS, Android, Windows, etc.)
  • Screensize
  • Referrer (Where the visitor originated from IE: PPCMode.com)

More data can be collected on mobile & tablet devices, such as if the visitor was browsing inside of an app and knowing specific manufacturer/name of the device used.

It depends on if the pixel server has other user data collected by other means, for example, Facebook. The tracking pixel can identify the visitor and match any events taken or any extra data about the visitor to the rest of their data profile. This is powerful because it gives marketers access to targeting a visitor based on data points they otherwise wouldn't have access too. Some ad networks can use this data for behavioral retargeting, create visitor profiles & lookalike audiences.

Illustration of tracking pixel data

Benefits of Using Tracking Pixels

Almost every marketer, webmaster and business owner uses some sort of tracking pixel today. Regardless if you're simply tracking web visitors with a tool such as Google Analytics, or more advanced tracking with the intent of building audience profiles & using behavioral retargeting the use of a tracking pixel is required.

Tracking pixels give marketers critical insights into the actions visitors are taking from various sources of web traffic. This allows the marketer to optimize their emails, websites, and marketing campaigns to both better serve their visitors and increase the revenue from web traffic. Being able to identify information about web visitors allows better ad targeting, personalized web experiences by recommending products, services, and content that is best tailored to the interests of the visitor.

  • Personalized web experience based on the visitor (products, services & content)
  • Better ad targeting increased conversion rates and ad usefulness
  • Overall better user experience when improvements are made based on data
  • Allows testing and optimizations with the data collected

Overall without tracking pixels, the internet wouldn't be what it is today. Data collection allows decision-makers to best suit their audience by improving their web experience. Tracking pixels are one of the main reasons the web is such a powerful tool it is today.

Disadvantages of Tracking Pixels

Due to the goal of a tracking pixel, visitors are often unaware that a tracking pixel is in use on the content they're visiting. This is due to there being no visual indicator that a tracking pixel is used. Regulators are attempting to help inform visitors of the data that is collected about them as they visit a website. GDPR in the EU is the currently most known such regulator effort to help inform the public of tracking pixels, similar laws have been voted on in various states in the US. This trend is likely to continue as more public outcry about data collection puts political pressure on policymakers.

Sometimes personalized content can make a visitor nervous as they may not be aware that so much data about them has been collected. Though rare I have seen using too much personalization in ad copy have a negative impact on the ROI of my campaigns.

Tracking pixels can also increase the bandwidth of a visitors web activities. Data collected has to be passed to and from the visitor device, both increasing load times and data usage. This may cause problems for web visitors with capped data plans or slow internet capabilities, having a negative impact.

  • Visitors are often unaware of the data collected
  • Privacy concerns and regulations such as GDPR make tracking pixels less effective
  • Too much personalization can discourage visitors
  • More bandwidth required decreased load times
  • Increases data usage for all web traffic

A cookie is a small file sent via your server or through Javascript with a small amount of data in it, such as a unique id number. Cookies allow your server to establish a "session" between the browser and web server. When a visitors browser requests a web page it's "stateless" meaning each request is unique. This causes problems if you're wanting to know the activity of your web traffic because every request would be viewed as unique, even if it was the same visitor clicking on several pages on your site. The cookie fixes this problem, by allowing your server to send an updated cookie to the visitor's browser, which is then stored in the browsers DOM. Since a server can read what is on the cookie, it can update the data when a new request happens.

Tracking pixels use cookies by creating a session. Once a session is established, the tracking pixel can identify which visitor is making to associate the tracked event with. If a cookie is placed on different websites, the tracking pixel can use this to identify the same user so long as they visit a site with the same cookie.

Put; cookies allow web servers to distinguish between different web visitor by assigning a unique id to the visitor and other small bits of information. The tracking pixel can collect data about the web activity and be able to determine which visitor it is based on if they have a cookie or not.

How Do I Get A Tracking Pixel?

Getting a tracking pixel depends on what you plan to use the tracking pixel for. If for example, you want to use Google Analytics to track your websites visitors, Google will provide you with a tracking code snippet that you have to place inside the HTML code of your website. This is also true if you're wanting to use conversion tracking or retargeting on an ad network such as Facebook. You'll have to go inside of your Facebook ads manager which will provide the required tracking pixel script, which you then install inside your HTML code.

How Do I Add A Tracking Pixel to My Email?

Just like installing a tracking pixel on a website, you will install your tracking pixel in the HTML of your email. Take note this does not work if you're sending a text-only email as this email format doesn't use HTML.

Usually, if you're using an email automation tool such as Convertkit (Can read my full guide here), they take care of all the tracking for emails that you send allowing you to get data such as open rates, click-through rates & link clicks.

Where Can I Get Retargeting Tracking Pixels?

If you plan on running a lot of paid traffic, it may be a good idea to set up the tracking pixels for each ad network early.

Here is a list of ad networks that currently have retargeting:

Other Ways To Use Tracking Pixels

  • Heat Mapping
  • Conversion Tracking
  • Analytics
  • Retargeting

If you have any questions or recommendations on how else to use tracking pixels, feel free to reach out to me!