How can I pass URL parameters into hidden form field?

Hi there,

I’m wondering how I can pass URL parameters into hidden form fields. Let’s say that…

-I’ve created a form with an ID of ‘#form’.
-The form has a hidden field with an ID of ‘#hidden’ that I want to pre-populate with the value of utm_source.
-The URL is ‘

Thanks in advance!

Hey John!

I’m actually building something for this exact problem at

In additional to auto filling form elements via url parameters, you can also personalize any part of your page with those same url parameters… I’ve been using Script to level up my no-code mastery, it’s enabled me to create some pretty cool stuff, you should definitely go check it out!

Take care my friend,


Hmm, your link is dead. Is your auto-fill script no longer a thing? I’d love to see how it’s done and have read other posts on it with no luck.

This solution works with hidden fields as well.
Note that in Webflow you’ll create the <input type="hidden"> element in an HTML Embed element.

Correct, no longer a thing!