Tracking technology is commonly used in emails by big compainies to track what you do on your device and create tailored content through emails.

Some of the largest brands in the UK including Tesco, Asos and HSBC use email pixels to monitor a person’s activity on their device, this means your emails may be being watched and tracked for data.

However, defenders of email pixels say they are commonplace in marketing tactics.

What are email spy pixels?

Email pixels are typically a .GIF or .PNG file inserted into an email through a line of code. The square images can be as small as one pixel by one pixel.

It is often not obvious to the email recipient that a spy pixel is present because they are transparent or placed somewhere discreet into the header or footer of the email. Recipients do not need to click on a link or do anything specific to activate them beyond opening the email they are embedded in.

The use of email pixels is governed in the UK and other parts of Europe by 2003's Privacy and Electronic Communications Regulations (Pecr) and 2016's General Data Protection Regulation (GDPR).

Rules require organisations to inform recipients of the pixels, and in most cases to obtain consent from the recipient.

What can email pixels be used for?

Email pixels can be used as a marketing tool by companies to log specific actions by the recipient of the email. These include:

  • If and when an email is opened
  • How many times an email is opened
  • What device or devices are involved when opening the email
  • The recipient’s rough physical location, deduced from their internet protocol (IP) address. In some cases the pixel will make it possible to see the street the recipient is located on
  • Which headlines, preview text, and send times/days generate more opens and clicks on the email
  • What email provider recipients use

This information can then be used by companies to focus on narrowing down their audiences, engage subscribers with more relevant content, and create tailored content through emails.

Companies like British Airways, TalkTalk, Vodafone, Sainsbury's, Tesco, HSBC, Marks & Spencer, Asos and Unilever have all been found to be using tracking pixels.

Email pixels can also lead to personalised follow ups to the email. This means recipients may receive emails from a sales person with lines such as: “I saw you open my email yesterday, but you haven’t replied yet”.

How to detect email pixels

There are several methods for detecting email pixels:

Detect pixels manually

The first method is to look for them manually. Although most pixels are hidden away in the email, some email providers (including Gmail, Outlook and Yahoo) don’t show external images by default. This is a safety precaution in case the image is a trackable one.

If you decline the option to ‘show external images by default’, tracking for that email will be disabled.

Recipients should note, this is not a complete solution, as emails may still contain an embedded image instead. Users will have to guess themselves whether the email contacts a tracking image or an actual image.

Don't click the email content link

If you are concerned about an email containing a tracking pixel then avoid clicking any links contained in the email.

In a similar tactic to avoid obtaining viruses from email, treat links to external websites or images within emails with caution.

If the email has a link to see the email content, then only click it when you are happy to let the sender know that you have read the message.

Set up automatic detection through third party

The most reliable method of detection is to use a third party app on your device to detect email pixels automatically.

One third party service is Ugly Email. The extension is available on Google Chrome, and will let the user see tracked emails in Gmail. Trocker is similar to Ugly Email, and is available on Chrome and Firefox. This will show users pixel tracks in their email inbox and identify links that are being tracked.

Even with extensions, some trackers may still be able to slip through, but they tend to be pretty adept at identifying the most obvious offenders.