Prefill Fields | ViralSweep Support Center

Prefilling fields lets you automatically pass user data into your ViralSweep form—so users don’t have to enter it themselves.

This is especially useful when directing users to a campaign after they’ve:

Logged into your site
Completed another form
Already shared their information elsewhere

👉 Looking for something specific?

Prefill just email addresses: Prefill Email Address
Automatically submit forms after prefilling: Auto Submit Forms

Implementation options

There are two ways to prefill fields in ViralSweep:

Option 1: JavaScript implementation

Use JavaScript to dynamically prefill form fields on page load.

How it works:

Add the script below before your campaign embed script (widget, full page, or lightbox)
Update the field values with your user’s data

<script>
function vs_widget_load_callback(){
  vs_prefill_field('first_name','John');
  vs_prefill_field('last_name','Smith');
  vs_prefill_field('email','[email protected]');
  vs_prefill_field('address','23 Main St');
  vs_prefill_field('address2','Apt 3');
  vs_prefill_field('city','Austin');
  vs_prefill_field('state','Texas');
  vs_prefill_field('zip','78704');
  vs_prefill_field('country','United States of America');
  vs_prefill_field('phone','2221111234');
  vs_prefill_field('birthday_month','May');
  vs_prefill_field('birthday_day','12');
  vs_prefill_field('birthday_year','1985');
  vs_prefill_field('code','1234');
  vs_prefill_field('18940_1525208752','Custom field value');
}
</script>

Using custom fields

Add the custom field to your form first
Use your browser’s Inspect tool to find the field ID
Replace the example ID (18940_1525208752) with your own

If you need help finding a field ID, contact support.

Option 2: URL parameters

You can also prefill fields by adding parameters to your campaign URL.

Supported parameters include:

vs_email
vs_first_name
vs_last_name
vs_phone
vs_address, vs_address2, vs_city, vs_state, vs_zip, vs_country
vs_birthday_month, vs_birthday_day, vs_birthday_year
vs_code

Example:

Base campaign URL:

https://app.viralsweep.com/vrlswp/full/d7f01f-70537?framed=1

With prefilled fields:

https://app.viralsweep.com/vrlswp/full/d7f01f-70537?framed=1
&vs_first_name=Josh
&vs_last_name=Smith
&[email protected]
&vs_phone=1234567899
&vs_address=123%20my%20street
&vs_address2=apt%203
&vs_city=Austin
&vs_state=Texas
&vs_zip=12345
&vs_birthday_month=December
&vs_birthday_day=8
&vs_birthday_year=1980
&vs_country=United%20States%20of%20America
&vs_code=1234

When users visit this link, the form will automatically be prefilled.

Important notes

Field values must match ViralSweep’s expected format
- Example: Use “United States of America” (not “USA”)
Replace static values with dynamic user data when possible
URL parameters must be properly encoded (e.g., spaces become %20)

Need help?

If you have any questions, our support team is here to help.

Click the chat icon in the lower-right corner to start a conversation.

Prefill Email Address