Track Opens with a Beacon

A beacon is an image you include in your emails to track which users open your emails. When the image loads, the system logs information about the user and their session. If you want to track opens, you must include a beacon in your templates and campaigns.

Including the beacon allows you to gather more specific data than whether the user opened the email, including the times of day the user typically reads email. You'll then be able to send campaign emails to each recipient based on a Personalized Send Time, or target groups of users with unique messaging. You'll also benefit from reporting that indicates the open rate of each of your campaigns.

Set a Beacon Image

You will maintain a single beacon image for your account, which you can insert in all templates using a simple Zephyr code.

By default, your account comes with the beacon image set to a "Powered by Sailthru" icon. It is recommended that you upload your own beacon image that will display in your emails. A transparent 1-pixel by 1-pixel gif or png is recommended so that your design is not dependent on the beacon image, though any image can be used, so long as it can be included in each message; for example, your company logo.

To upload a beacon image, visit your Email Settings Page (located under Settings > Channels > Email) and upload a PNG, GIF, or JPG file under Beacon Image. After you've uploaded this image once, you do not need to do so again unless you want to change beacons.

Note: Even after completing this step, you will still need to ensure that the Zephyr code to display the beacon is included in all email templates.

Include the Beacon

You must include the beacon in each of your triggered and campaign emails/templates in order to track opens for their sends.

There are a few options for inserting a beacon image in your template or campaign code. Regardless of the one you choose, it is recommended that you place your beacon near the top of your template in case your emails are clipped by the recipient's email host, and the full message is not displayed. Beacons in a clipped region of an email will not be counted towards opens.

Note: While we recommend placing your beacon near the top of your template or code, we do not recommend placing it within the <head> tags. Some ISPs strip certain HTML elements, like head tags. Placing your beacon on line 1 of your template (before any HTML elements) or just after the body tag should ensure that it tracks properly.
  • To include the beacon image and have it linked to its default location, use the Zephyr code {beacon}.
    • The default link location for the default beacon logo is
    • The default link location for your custom beacon image is your domain.
  • If you want to set a different link, for example to a subpage of your website, use {beacon_src} to access the full beacon URL. For example:<span class="c9"><a href=""><img src="{beacon_src}"/></a></span>
  • If you want the beacon image displayed without being hyperlinked, you can simply insert the image using {beacon_src}. For example:<span class="c9"><img src="{beacon_src}" alt="logo alt text here" /></span>

In addition to your sends, the beacon image will render in the Preview tab when you are editing templates or campaigns and in test emails.

Note: If you are using HTTPS images in your email, recipients may get browser security warnings if you also have any non-secure images (HTTP) in your email. In this scenario, you'll need to use an HTTPS beacon. Use <span class="c9">{beacon_ssl}</span> or  <span class="c9">{beacon_src_ssl}</span>) to accomplish this.

Limitations on Tracking Opens

There may be a small percentage of users who open and read your email without enabling images in their email client. Those users cannot be tracked unless they click a link in a message. Otherwise, they will not be included in open rates. For more on campaign reporting, see the Reporting Overview page.

Use an Additional Pixel

If you wish to use any additional tracking pixels in your messaging, add the pixel inside an image tag (<img />). Your system data won't be affected by these pixels, but the data will pass to the application that generated the pixel.

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