FeaturesPre-Populate Forms

Pre-Populate Forms

Pre-populate forms by passing known values into hidden fields through the form URL. This lets you carry campaign, CRM, customer, or referral data into the submission without asking respondents to type it.

Add a hidden field for URL parameters

Pre-population is best for values you already know before the respondent opens the form, such as email, utm_source, customer_id, referral_code, or plan.

How pre-population works

Create a hidden field, save the form, then pass a matching query parameter in the form URL. Makeform reads that parameter and saves it with the response.

Example:

https://makeform.ai/f/customer-intake?email=maya@example.com&plan=pro

In this example:

  • email fills a hidden field named email.
  • plan fills a hidden field named plan.

You can also use that hidden value inside form copy. Click or type @ and choose the parameter from the variable menu.

Create a hidden parameter

  1. Open your form in the builder.
  2. Go to the form settings.
  3. Add a Hidden Field.
  4. Give it a stable field name, such as email, utm_source, customer_id, referral_code, plan, or company.
  5. Save or update the form after adding the hidden field.
  6. Publish or preview the form.
  7. Add a matching query parameter to the form URL.

Build a pre-populated link

Start with the form URL, then add a question mark and key-value pairs:

?email=maya@example.com&plan=pro&utm_source=newsletter

Use & between each value.

If a value contains spaces or special characters, encode it:

company=Acme%20Studio

Use the parameter in form copy

Hidden parameters are not shown as editable fields, but you can reference them in questions, descriptions, text blocks, or ending pages.

For example, if your hidden field is named email, you can insert it into copy as:

We will send the receipt to {{email}}.

Use the @ menu in the builder to insert the parameter instead of typing the variable manually.

Select a hidden field from the variable menu

Respondent experience

The respondent does not see or edit the hidden field. Makeform stores the parameter with the response, and any visible copy that references the parameter updates when the form loads.

Common use cases

Use caseValues to pass
Newsletter campaignutm_source, campaign, segment
CRM lead routingcompany, owner, lead_id
Customer supportaccount_id, issue_type, customer_tier
Event registrationticket_type, referrer, discount_code

Testing checklist

  • Open the link in a private browser window.
  • Confirm hidden tracking fields appear in the submission data.
  • Confirm any copy that references the parameter renders correctly.
  • Test values with spaces and special characters.
  • Submit a test response and review the saved values.

Troubleshooting

A hidden field does not receive a value

Check that the query parameter name matches the field name exactly.

Spaces appear incorrectly

Encode spaces as %20 or use a URL builder before sending the link.

The value is visible but should be hidden

Move that value to a hidden field so respondents cannot edit it.

A variable does not render in copy

Confirm the hidden field exists before you insert it, then use the @ menu to select the parameter again.

Answer PipingRedirect After Submission