Configure pre-filling of a hidden field

You can use hidden fields to automatically send technical or auxiliary parameters, such as UTM tags, to the form. This way, you can add additional info to user responses for analytics and statistics.

Let's say you created a form and posted it on different websites. Now you want to know which website the user filled out the form on. To find this out, use the utm_source UTM tag.

Add a hidden Source of responses field to the form. Add a GET parameter to the link, and its value will automatically be sent to the hidden field. Then you can see where responses came from.

To set up a hidden parameter for this example:

1. Add a Short text question titled Source of responses to the form.

2. Enable Hidden question for this question.

3. In the Question ID field, specify utm_source: that's the GET parameter name.

4. Get a link to the form and add the ?utm_source=site_name_1 GET parameter at the end.

   • Sample link to the form without the GET parameter:
     https://forms.yandex.com/u/6191b18d99e21b1********/

   • Sample link to the form with the GET parameter:
     https://forms.yandex.com/u/6191b18d99e21b1********?utm_source=site_name_1

5. Post the form link with the GET parameter on the website.

6. In the same way, create another link to be placed on another website. To do this, add the GET parameter ?utm_source=site_name_2 at the end of the URL.

7. When a user follows the link, the site_name_1 or site_name_2 value is automatically entered in the hidden Source of responses field. Based on this value, you can determine on which website the user filled out your form.

To enable pre-filling of a hidden field when embedding a form in a website with an iframe, specify the URL with the GET parameters in the iframe embed code.