With Sailthru’s Overlays, engage site visitors with targeted messaging as they browse.

The overlay UI showing a preview of the overlay and the website it appears on

Create Overlays on your site with an easy-to-use interface in My Sailthru. Display user signup forms, special offers, and more–each as a modal window or a bar at the top of the page.

  • Target users based on their Sailthru lists or onsite activity
  • Restrict messages to specific pages or page types
  • Create content with a simple WYSIWYG, uploaded images, or custom HTML

Overlays require Site Personalization Manager (SPM). If you do not see the SPM menu at the top of My Sailthru, please contact us to inquire about adding these features. Overlays also require that the latest Sailthru JS is embedded on your site.

Overlay Goals

Each overlay can be displayed as a modal window or a top bar that the user can close or interact with, for example, by entering information and clicking a “submit” button.

You can select from two types of overlay goals, each including your own custom message and design:

  • Promote Something (Announcement) – A simple message without any interactive elements.
  • Grow Mailing List (User Signup) – Include a form for the user to enter their email address.

Overlay List and Metrics

You can view details of all existing overlays when you open the Overlays section of My Sailthru. For each overlay, the following information is displayed:

  • Name – Internal name you have set for the overlay. Click to view or edit its settings.
  • Status – Active or inactive.
  • Schedule – The start and end time for the display of the overlay, or “Indefinite”.

    Note: An Overlay must also be active in order to be displayed, regardless of schedule time. Even if currently scheduled, an inactive Overlay will not display.

  • Goal – The type of challenge to solve for with the overlay: Announcement or User Signup.
  • Audience – The targeted users: Lists, Anonymous, Known, or All users.
  • Views – Number of times the overlay was displayed.
  • Click Rate – The number of clicks on a link within the Overlay, inclusive of anything that is marked up with an anchor tag set . This excludes any clicks on the X to close the Overlay or on the Submit button.
  • Conversion Rate – The number of conversions divided by views. Conversions are currently only available in User Signup Overlays.

Create an Overlay

Choose an Overlay Template

When you click New Overlay, the Choose a basic template screen opens:

Click an image to select either bar or modal for the type of Overlay you want to create. The Overlay Builder opens.

The Overlay Builder

On the Overlays page, when you click New Overlay or click the name of an existing overlay, the Overlay Builder opens.

  • The Top Bar displays the editable Overlay Name and Status (Active or Inactive), its Last Saved Date/Time, and a Save button to commit your changes.

    Pre-click and Post-click options are available for the Email Signup modal and bar Overlays. Post-click shows your selected Display Message.

    The overlay will not be displayed to any visitors when set to “Inactive.”

  • The Side Bar offers the tools for creating and editing your overlay, with five tabs: Setup, Style, Content, Targeting, Preview. Note that different options may be displayed on each tab depending on the type of overlay you have selected.
    • Setup – Set the background preview URL and Overlay dismissal option.
      Setup options vary depending on the type of Overlay you’re creating.

      Announcement Email Signup
    • Style – Set the overlay position, color, optional image, and background opacity. Options vary depending on the Overlay type you’re creating.
      Bar Overlay Modal Overlay
    • Content – Enter the overlay content. Content options vary depending on the Overlay type you’re creating.
      Announcement Email Signup
    • Targeting – Select which pages, users, or user activity should launch the overlay, with an optional frequency and time period.
    • Preview – See a live preview of your Overlay exactly as it will appear on your site after all CSS processing. It will open up in a new tab and load the Overlay on your site, provided the Sailthru Javascript tag is on the target page.
  • The Preview pane shows the current appearance of your overlay against the URL you set as the background.
    • Set the preview URL in the Setup tab Change Background URL dialog box.

For more information about any of the individual settings within the builder, see Overlay Settings, below.

Overlay Settings


Setting Options Availability
Change Background URL Enter the URL for your selected background. All Overlays
List to add subscribers to The lists to which the user should be added. User Sign-Up
Source to attribute to each subscribers’ profile Enter a source var which will be added to each subscriber’s profile. User Sign-Up
Confirm subscription via email If enabled, the selected Confirmed Opt-In template is sent and the user is not added to the list until they click the link you have provided in the email. If disabled, the user is added to the Destination Lists immediately upon their submission of their email address, and the sailthru_hid cookie is set to identify the user for current and future browsing sessions.

Using confirmed opt-in can cut down on the number of bot sign-ups.

User Sign-Up
Overlay cannot be dismissed When selected, the Overlay cannot be dismissed. All Overlays

Confirmed opt-in with the signup_confirm() function

  1. A user clicks to sign up from your Overlay. Sailthru creates an array called “signup_lists”.
    • The array contains the lists you selected from the Destination List drop-down menu. For example, if you select “Daily Newsletter” and “Weekly Deals”, then the signup_lists array resembles the following:

      {signup_lists=["Daily Newsletter", "Weekly Deals"]}

  2. Automatically pipe the array into the signup_confirm() function. The function is contained in the link you send in your signup confirmation template.

    Click here to confirm your email address

  3. When the user clicks the link in the confirmation email, Sailthru adds them to the selected lists.
  4. The user is redirected to a confirmation page. To use a custom page instead of your default Thank You page, create an “Other”-type Hosted page named “signup-confirm”.

    Note: The type “Other” and the name “signup-confirm” are required to access and edit the signup confirmation page.


Setting Options Availability
Overlay Type
  • Modal – Overlay is displayed as a pop-up in your page (in the same browser window as your page).
  • Bar – Overlay is displayed as a bar located at the top of your page.
All Overlays
Dimensions For desktop browsing environments only. Sets the maximum width in pixels for the Overlay. If the viewport width is less than the value in this field, the modal will adapt responsively, reflow the content of the overlay, and fit to the narrower viewport size. When the viewport is 550px or less, a mobile view is initiated which always sets the Overlay width to 90% of the current viewport width. Modals
Height The minimum height when the content within the bar does not force a greater height. Bars
Position Select whether the modal should be located near the top, middle, or bottom of the browser window. The modal will always be centered horizontally on the page. Modals
Padding Set the padding for your Overlay’s content. Modals
Background Color The background color for your overlay.
Use the color-picker tools, or manually enter a 6-character HTML hex code or set of R/G/B color values. Manually entering either of these is recommended if you are attempting to match your brand’s color.
The last slider, which corresponds to the “A” box, specifies the overlay’s opacity on a scale of 0 to 100.
All Overlays
Border Set the pixel width of the Overlay border. All Overlays
Background Image You can use this feature to upload an image to display in the overlay. The image can be displayed above, below, or alongside text, or as a background image.
Note: It is also possible to display an inline image that is instead hosted on your site or elsewhere by embedding it with your own custom HTML.
To upload an image, click the toggle next to the words “Background Image”. Then:

  1. Click “upload image” and select an image from your computer.
  2. Under Position, select whether you want the image to show:
    • Above other content
    • Below other content
    • To the left of other content
    • To the right of other content
    • Behind other content. When this option is selected, additional Background Image Options are displayed.
      1. Fit – Resizes the image to fit inside the overlay, maintaining the image’s aspect ratio. Will cause letterboxing (background color to appear) above or beside the image if it does not match the overlay’s aspect ratio.
      2. Fill – Resizes the image to fit the width or height of the overlay-matching whichever side of the image is short of the overlay’s aspect ratio-so that there is no letterboxing and may be some cropping.
      3. Tile – Orients the image at the top-left of the overlay. Repeats image if it is smaller than the overlay. Maintains the image’s original size and aspect ratio.
      4. Center – Preserves image’s original size and aspect ratio. Cropping will occur if the image is larger than the overlay.
Background Screen Opacity The percentage visibility of the page behind the overlay when the overlay is displayed. All Overlays
Page Flow Inline – Pushes the page content down
Fixed – Covers the top portion of the page
Animation Because the bar loads after your page, customers will experience a “jump” – page content will move down to make space for the bar. Using animation helps to ease this transition. Bars
Custom CSS Add custom css to style your Overlay. All Overlays


Note: Safari does not support changing text alignment of drop-down elements (<select>). They will always be left aligned.

Setting Options Availability
Text Headline text. Use the editor options to change the font, size, color, and other attributes. HTML is supported but not required. All Overlays
Text Detail text. The same options are available that exist for the Headline. HTML is supported and you may toggle this field off. Modals
Email Input Set and format email field placeholder text. User Sign Up
Button Select a button color, enter button copy text, and configure a Post-Click Action.
For the Post-Click Action, you may either enter a message to display or a URL to which the user will be redirected. If you enter a message, after the user submits their email address, the message is displayed for 5 seconds before the overlay is automatically closed.

For the Post-Click Redirect, the user’s submitted email address will be automatically appended to the URL as a query parameter named em. For example, if you enter example.com/?utm_source=spm#welcome and your user enters user@example.com, the user will be redirected to example.com/?utm_source=spm&em=user%40example.com#welcome

Note that if you have included custom JavaScript functions to handle Sailthru’s response to the user’s email submission, your function may be configured to override the above Post-Click Actions. See the Sailthru.initfunction’s onSignupSuccess/onSignupError parameters.

User Sign Up


Setting Options Availability
Where You can select to display the overlay “Sitewide” or only on “Specific Page(s)”.

When you select “Specific Page(s)”, additional options are displayed for selecting those pages.

Click “Add URL” to add at least one URL or URL pattern. A field for the URL/pattern is displayed, and it will be treated based on your chosen type of matching below: Simple, Exact, or Contains. (See URL Targeting Details.) If you add multiple URLs/patterns, they are treated with ‘OR’ logic-the URL must match only one of your entries in order for the overlay to be displayed.

All Overlays
Who Display the user to:

  • List(s) – Only those visitors who exist on one or more of your Sailthru Lists
  • Everyone – All visitors
  • Logged-in visitors only
  • Anonymous visitors only


  • Desktop only – Enables the option to display on page Exit Intent
  • Desktop & mobile
  • Mobile only
All Overlays
When: Exit Intent Display the overlay when the user moves their mouse to within 20 pixels of the top of the browser’s viewport, indicating that they might close the window or enter a different address. Desktop Only
When: Trigger
  • Display the overlay to a given user only after your chosen number of:
    • Pageviews (during the current session)
    • Value of cart
  • Display the overlay when a user tries to leave the site (desktop only)

A user’s session is considered to have ended 30 minutes after the user’s last pageview.

All Overlays
When: Frequency Capping Limit the number of times that the Overlay may be displayed for the user:

  • Once per visit – Once per site session. A session is is considered to have ended when the user’s last pageview occurred more than 30 minutes ago.
  • Once ever – Only once for this user. (If the user visits again in a new browser or with cleared cookies, the user may see the overlay again.)
All Overlays
When: Start and End Dates
  • Start Date – The date to begin displaying an active Overlay.
    • Will not start an inactive Overlay
    • When blank, the Overlay will display as soon as it is set to Active.
  • End Date – The date to stop displaying an Overlay.
    • When blank, the Overlay will continue running until it is set to Inactive.
All Overlays

URL Targeting Details

URL Targeting allows you to specify which of your site’s URLs will display the overlay. Four types of URL targeting are available:

Type Definition Examples
Simple Enter a URL and Sailthru will disregard any query string and protocol, matching only those URLs that contain the same domain and path or file extension.

example.com/category or

Matches Include:

Does Not Match:


Matches Include:

Does Not Match:

Exact Matches the entered URL exactly. Trailing slashes will be ignored.


Matches Include:

Does Not Match:

Contains Matches only URLs that contain or exactly match the entered text


Matches Include:

Does Not Match:


Matches Include:

Does Not Match:

Pattern Matches only URLs that contain specified “regular expression” pattern within them. Enter:

Matches include:

Does not match:


Matches include:

Does not match:


Matches include:

Does not match:

Test Your Overlay On-Site

You can use a special query parameter in your site’s URLs to view any overlay for testing purposes, regardless of its status (active or inactive) and targeting rules.

Stats are not counted for this feature.

Simply append the following to your URL:


To obtain the overlayID, open the overlay’s configuration page within My Sailthru. The ID is the portion of the URL after the last slash. For example:


Capture Additional Data in an Overlay

Add form elements to your Overlays to collect and record user information that’s relevant to your marketing efforts. Any information you captured in a standard form you can now capture through your Overlays. Segment, target, and message your users more effectively with additional information.

Using HTML Elements and Attributes

The best way to collect more user information on signup is with HTML form elements. For example, the following markup indicates the class, var name, and var attribute:

<input type="text" class="sailthru-var" data-var-name="first_name" data-var-attribute="value">

The sailthru-var class indicates to Sailthru JavaScript that the element contains var data. The markup above also specifies the var name and the name of the element that contains the var value.

Attribute Description Allowed Values
class Associates CSS styles with the element. Sailthru JS will use a special class to indicate that the element contains var data. sailthru-var
data-var-name Specifies the name of the var to populate. Any valid profile var name.
data-var-attribute Specifies the name of the element attribute that contains the var value. Any valid HTML element attribute name.

Capture vars using element tags

Here are some examples of capturing user information using element tags:

Capture a user’s first name
<input type="text" class="sailthru-var" data-var-name="first_name" data-var-attribute="value">
Capture a user’s favorite subject
What's your favorite subject? 
<select class="sailthru-var" data-var-name="favorite_subject" data-var-attribute="value">
  <option value="ela">Readin'</option>
  <option value="law">Ritin'</option>
  <option value="math">Rythmatic</option>
Capture a user’s gender

The option name must match the data-var-name. In this example, the data-var-name is gender, which is matched by the input element’s name.

<label>Gender: </label>
<form class="sailthru-var" data-var-name="gender" data-var-attribute="value">
  <input type="radio" name="gender" value="male">Male
  <input type="radio" name="gender" value="female">Female
  <input type="radio" name="gender" value="other">Other  
Capture a user’s birth date
<input type="date" class="sailthru-var" data-var-name="birth_date" data-var-attribute="value"/>

Signup var Precedence

userSignup and userSignupConfirmedOptIn ,two functions in the Sailthru JavaScript API, use the following var sources in this order of precedence:

  1. Sailthru.signupVars
  2. HTML elements
  3. User vars passed through the “integration” module to the signup functions:

    Sailthru.integration("userSignup", {vars: {...}, ...}).

    This can happen at user conversion or at any time.