What Is a Tracking Pixel? (And How It Works)

Last updated


Daniel Wade


July 28, 2022

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If you already haven't come across the phrase 'tracking pixel' and you're in the marketing industry, you will. Tracking pixels allow advertisers to gather user data for mobile, email, and web marketing.

Typically, tracking pixels are a technique used in emails or web pages to collect user behavior data.

Tracking pixels are typically a JavaScript or HTML code snippet, and allows marketers to track different events and actions a user takes. Marketers can utilize these actions for conversion tracking, behavioral retargeting, and tracking user behavior.


Table of contents

What Is A Tracking Pixel?

Tracking pixels are 1x1 pixel graphics used in tracking site conversions, user behavior, web traffic, and multiple other metrics at the site's server level. Other terms commonly used to define them include web bug, web beacon, clear GIF, and pixel tag.

These pixels can assist you in assessing your marketing plans and boost sales. Additionally, they can prevent you from investing in unproductive marketing campaigns, helping you focus on efficient marketing approaches and optimize your resources.

Ideally, pixel tags are petite pixel-sized images often hidden and embedded in virtually everything, from emails to banner ads. Despite being small, they are useful for helping marketers capture helpful information for the web analytics pack. Tracking pixel codes allow firms to track sales conversions, email opens, events, web visits, among other web activities.

A tracking pixel can provide you with data about your users, including their location and the kind of gadget they use. These tags can disclose whether your users are coming from paid searches on Facebook, Google, or Twitter. They can also be used to identify the most engaging audience and the best time for ROI.

Furthermore, tracking pixels permit Google Analytics and related services to inform firms how many visitors their sites receive and how many have viewed their digital ads.

How Does A Tracking Pixel Work?

The relatively tracking pixels' small size is a fundamental aspect of their functionality. They are deliberately concealed in email or web page backgrounds to prevent them from interfering with user experience. They are hidden to allow a back-end process that doesn't distract from a marketing email or website's content.

Tracking pixels usually embed in HTML codes of online ads, marketing emails, or websites. They are recovered from servers each time users loads the ads, emails, or websites into their browsers. These servers then send the tags to a user's specific IP address and then logs them. As such, the servers count the total retrievals.

Once the tracking pixel code snippet is added to the email or website's HTML code, the pixel starts to track different data about the user viewing the page. This user information is gathered once this tracking pixel is loaded through the user's browser.

After the pixel is processed in the user browser, this process is called the 'pixel firing.' It means that the user's data was sent to the pixel server gathering the data. When visitors load emails or websites, data is passed from the user agent. User agents have information on the users that is valuable to marketers, including:

  • Browser (Opera, Firefox, Chrome, etc.)
  • IP Address (Internet Service Provider and location information)
  • Operating System (Android, iOS, Windows)
  • Type of Device (Desktop, Mobile, or Tablet)
  • Screen size

In simple terms, when users visit websites, opens emails, or views digital ads, they are simply requesting the server to download tracking pixels that are embedded in the content. Despite the users having no idea of this, the information collected can help businesses and brands create user-specific content.

Uses of Tracking Pixels

The essential purpose of tracking pixels is tracking unique page views. Email marketers, advertisers, and web operators using tracking pixels can assess the servers' logs and identify the number of views their content receives.

Traffic data received through tracking pixels can further be evaluated for advertising and marketing purposes. Accurate assessment of the IP addresses may offer an idea of users' geographic origin and the types of operating systems and gadgets they visit websites with.

A tracking pixel also works across servers and websites, offering advertisers and website owners a better view of why users visit the site and what they want. With this information, you can customize ads and content to suit user preferences and needs-targeted marketing strategy. Various ad networks can apply this data for effective behavioral retargeting and build unique lookalike audiences & visitor profiles.

How Is Pixel Tracking Integrated Into the HTML CODE?

Installation of tracking pixels differs depending on the system. It can be done through the content management system used or integrating it directly in the website or email's source code.

Customarily, the web analysis tools requiring this pixel implemented like Google Analytics or Facebook provide comprehensive implementation instructions.

Tracking pixels may be integrated into a website's source code as outlined below:

<img src="URL pixel tracking" width="0" height="0">

<img src="URL pixel tracking" style="position:absolute; visibility:hidden">

<img src="URL pixel tracking" style="display:none">

Once visitors access sites, tracking pixels are loaded away from the servers through the <img> tag. Usually, the 'Uniform Resource Locator tracking pixel' demonstrates the image's location within the server, while style attributes 'display: none' and 'visibility: hidden' state that this image is either hidden or even not displayed.

Additionally, just like the initial example, the image's height and width can be well set to zero ( 0). This will hinder the pixel tracking display.

The Difference Between Cookies and Tracking Pixels

Cookies are small files sent through Javascript or your server with small data amounts like unique ID numbers. A cookie allows your server to establish a unique 'session' between the web-server and the browser.

When visitors' browsers request a web page, they are 'stateless,' meaning that every request is unique. This is problematic, especially if you want to know your web traffic activities since each request will be viewed as unique. This is the case even where it is the same visitor browsing different pages on your website.

Cookies fix this issue by allowing your server to dispatch updated cookies to the visitor's browsers. These cookies are then stored in the visitors' browser's DOM. Since servers can read everything on the cookie, they can update the data with every new request.

Cookies have code that web-servers utilize to store particular data in users' browsers. This data can be retrievable later for various uses. Ad servers like DoubleClick usually use cookies in setting distinctive user IDs. This way, they permit them to pinpoint the same users across various touchpoints.

When ad servers receive ad requests from users who don't have such cookies yet, the ad servers assign them new and unique IDs. Typically, these IDs are random alphanumeric strings. For every new request, the cookie returns a similar distinctive ID to allow the ad servers to identify the same users.

Since the ad servers' record all requests, reports can be well-produced that pinpoint every touchpoint for every user. This unique functionality does not exist for adding up pixels.

Benefits of Using Tracking Pixels

  • Personalized web experience unique to each visitor

A tracking pixel provides marketers with crucial insight into their visitors from different web traffic sources. This way, marketers can optimize their marketing campaigns, websites, and emails to better suit their visitors and boost revenue from increased web traffic.

  • Better ad targeting boosting conversion rates and ad effectiveness

With tracking pixels, marketers can identify web visitors' information. This allows personalized web experiences and better ad targeting by recommending content, services, and products customized to suit visitor needs.

  • Overall better user experience

Data collection through tracking pixels allows marketers to create user-specific content based on the information collected. This enhances the overall web experience for the users visiting your website.

  • Effective Marketing Campaigns

A tracking pixel can be useful in the practical analysis and testing of content and sent emails. This is because they reveal the opening rates of various newsletters or emails through user statistics data. What's more, optimization is done based on user data across multiple metrics.

Disadvantages of Tracking Pixels

  • Privacy concerns (Visitors are unaware of the information collected)

When you consider tracking pixels' objective, visitors are usually unaware they are active on their browsing sites. This is because there is no visual indicator of the presence or use of a tracking pixel. Nonetheless, regulators such as the EU-affiliated GDPR inform visitors of data gathered on them when they visit websites.

  • More bandwidth required and decreased load times

The use of a tracking pixel may also increase the bandwidth of visitors' web activities. Since data gathered must be passed from and to the visitors' gadgets, this increased data usage and load times.

  • Increased data usage for all web traffic

With increased load times and more bandwidth needed, this may turn quite problematic, especially for users with slow internet capabilities and capped data plans. This increases data usage for web traffic.

Protection of Users From Tracking Pixels

Users can follow several specific steps to ensure they protect themselves from data harvesting by a tracking pixel. Some of the most effective ways you can do this include:

  • Modifying email and browser settings to increase restrictions on what information the sites they visit can access.

The limits should be so that external graphics are only supported after granting permissions. Also, HTML emails must be restricted. You can also set suitable firewall settings to increase restrictions.

  • Using the proxy servers or anonymously surfing with Tor browser. This will prevent the tracking pixels download.
  • By using specific browser extensions to make the tracking pixels visible.
  • Deactivating scripts support in your browser

This will prevent the gathering of additional user data like OS or browser type. Nevertheless, this may restrict other internet functions under certain conditions.

What Is a Tracking Pixel? (And How It Works)


Daniel Wade

Daniel Wade

After working for multiple digital advertising agencies and managing hundreds of client accounts and spending millions of dollars via Google Ads, Facebook Ads, Native Ads and Direct Media Buying, I took things out on my own and started SparrowBoost. Now, my tight-knit team and I continue to get smarter and more efficient at running our own campaigns and we share our knowledge with you.

Learn more about SparrowBoost