Why Use URL Parameters to Auto-Populate Form Fields

When you send a contact a link to a landing page or form, you already know who they are — asking them to retype their name, email, or other details creates unnecessary friction and reduces form completion rates. URL parameters let you pre-fill specific form fields automatically by passing values through the link URL. When the contact clicks the link, the form opens with those fields already filled in, so they only need to confirm or complete the remaining fields. This is especially useful for personalized campaigns, retargeting links, and affiliate tracking.

How to Set Up URL Parameter Auto-Population on a Form Field

1. Open the form or landing page you want to modify in your Keap™ form builder by clicking on the form name from your forms list.

   The screenshot below shows the forms list in Keap with a form selected. The form name appears as a clickable link in the list. Clicking the form name opens the form builder for that form.

   

2. In the form builder, click the field you want to configure for URL parameter auto-population. Clicking the field opens its field settings panel.

   The screenshot below shows the form builder in Keap with a field selected. The selected field is highlighted on the form canvas and the field settings panel appears on the right side of the screen. The field settings panel contains configuration options including the URL parameter setting.

   

3. In the field settings panel, enter the name of the URL parameter you want to use to populate this field. The URL parameter name is the keyword that will appear in the URL to pass a value to this field. Choose a short, descriptive parameter name with no spaces.

   The screenshot below shows the URL parameter field in the field settings panel in Keap. The URL parameter input field appears as a labeled text field within the settings panel. An example parameter name is entered in the field to illustrate the expected format.

   

4. Click Publish or Republish to save your changes and make the updated form live. URL parameter auto-population will not work until the form has been published with the new parameter settings.

   The screenshot below shows the Publish or Republish button in the Keap form builder. The button appears in the top right corner of the form builder. Clicking Publish or Republish saves all changes and updates the live version of the form.

   

5. Test the URL parameter by opening your form URL in a browser and adding the parameter and value to the end of the URL using the following format:

   https://yourformurl.com?parametername=value

   Replace parametername with the parameter name you entered in step 3, and replace value with the text you want to pre-fill in the field. If your URL already contains a question mark, use an ampersand (&) instead of a question mark to add the parameter.

   The screenshot below shows an example of a form URL with a URL parameter and value appended in a browser address bar. The URL format shows the base form URL followed by a question mark, the parameter name, an equals sign, and the parameter value. The browser address bar is the only element visible in this screenshot.

   

6. Confirm the setup is working by verifying that the configured field is pre-filled with the value you passed in the URL when the form loads in the browser.

   The screenshot below shows the form open in a browser with the configured field pre-filled with the URL parameter value. The pre-filled field displays the value that was passed through the URL. All other form fields that were not configured with a URL parameter appear empty.

   

Frequently Asked Questions

What does this article cover?

This article covers how to configure a form field to accept a URL parameter for auto-population in Keap, and how to test the configuration. This article does not cover creating forms or landing pages from scratch. For help building forms in Keap, visit the Keap Help Center.

Can I use URL parameters to pre-fill more than one field at a time?

Yes. You can configure multiple fields on the same form with different URL parameters. To pre-fill multiple fields at once, add each parameter and value pair to the URL separated by an ampersand (&). For example: https://yourformurl.com?firstname=John&email=john@example.com

Does the contact have to use the pre-filled value or can they change it?

The pre-filled value is editable by the contact. URL parameter auto-population fills the field with the provided value as a default, but the contact can modify the field before submitting the form. If you need a field value to be locked and uneditable, use a hidden field instead of a visible form field.

Will URL parameter auto-population work if the form has not been republished after adding the parameter?

No. The form must be published or republished after configuring the URL parameter setting for the changes to take effect on the live form. If you configure a URL parameter but do not republish the form, the field will not be pre-filled when the URL parameter is passed.

What format should I use for the URL parameter name?

URL parameter names should be short, descriptive, and contain no spaces. Use lowercase letters and hyphens or underscores if needed to separate words. For example, firstname, email, or promo-code are all valid parameter name formats. The parameter name you enter in the field settings must match exactly the parameter name used in the URL — parameter names are case-sensitive.