Add Hidden Fields: Unbounce Forms
This guide explains how to add hidden fields in Unbounce and connect them with your CRM. Hidden fields are useful for passing information (like UTM parameters, user IDs, or campaign data) from your website into the form without the user seeing or editing them.
Step 1: Add Hidden Fields in Unbounce
- Open your landing page in the Unbounce Builder.
- Select the Form element on your page.
- In the Form Fields panel → click + Add a Field.
- Choose Hidden Field.
- Label →
channel - The Field Name is what will be sent in your lead data.
- Add the remaining hidden fields:
channeldrilldown1,channeldrilldown2,channeldrilldown3,channeldrilldown4,landing_page,landing_page_group.
These fields won’t be visible to users but will capture values from your URL parameters or scripts.
Video: Step-by-step walkthrough
Step 2: Embed Your Form as an iFrame
To embed your form, you need to use an <iframe> tag on your site.
Basic iFrame Example
<iframe
src="https://form.com/"
width="100%"
height="400"
frameborder="0">
</iframe>This is the standard way to embed a form using an iFrame.
Enable Attry Tracking
To allow our script to track this iFrame, add the attribute data-attry-iframe to your <iframe> tag:
<iframe
src="https://form.com/"
data-attry-iframe
width="100%"
height="400"
frameborder="0">
</iframe>The data-attry-iframe attribute signals our script to automatically populate and track form data inside the embedded iFrame.
Step 4: Add Attry Code To Your Site
How To Add Code To Your Site
Option 1: Using the WP Admin (no code editor)
- Log into WordPress Admin.
- Go to Appearance → Theme File Editor (or Appearance → Editor if block theme).
- Open
header.php. - Paste the Attry script before the closing
</head>tag. - Save changes.
Important
The Attry code shown below is an example only. Your unique snippet must be copied from your Attry Dashboard and added to your site. Do not use the example script verbatim.
Example <head> block
<head>
<!-- Attry Main Script -->
<script src="https://cdn.attry.app/cdn/snippet/v1.js"></script>
<!-- Attry iFrame Adapter -->
<script src="https://cdn.attry.app/cdn/adapters/iframe-prefill/v1.js"></script>
<!-- Configure Attry -->
<script>
window.Attry.setConfig({
debug: true, // set to false in production
iframeTagging: {
enabled: true,
paramMap: {
channel: "channel",
channeldrilldown1: "channeldrilldown1",
channeldrilldown2: "channeldrilldown2",
channeldrilldown3: "channeldrilldown3",
channeldrilldown4: "channeldrilldown4",
landing_page: "landing_page",
landing_page_group: "landing_page_group"
},
preserveExisting: false
}
});
</script>
</head>