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Hidden values

Hidden values are form-level keys that accept values from URL parameters or embed attributes. Respondents do not see them as questions, but Fomr can use them in form text and store them with each submission.

Use hidden values for campaign tags, customer IDs, source tracking, or other context you already know before someone opens the form.

Declare each key before you pass values into a link or embed.

  1. Open a form in the editor

  2. Click Hidden values in the editor dock

  3. Enter a key, such as utm_campaign or customer_id

  4. Click the add button

Keys must start with a lowercase letter. Use only lowercase letters, numbers, dashes, and underscores.

After you declare keys, the Share panel can build links with values attached.

  1. Open Share

  2. Fill in the fields under Hidden values

  3. Copy the generated link

  4. Share that link with the audience that should carry those values

A link with a hidden value looks like this:

https://fomr.io/s/example?utm_campaign=spring_launch

Only declared keys are captured with responses.

Hidden values can also travel through embed attributes.

  1. Open Configure > Add to website

  2. Choose an embed type

  3. Turn on Hidden values in the embed options

  4. Fill in the values and copy the embed code

Embed attributes use the data-fomr-param-* format. For example, the utm_campaign key becomes data-fomr-param-utm_campaign="spring_launch".

Declared hidden values appear in the same @ menu as answer pipes. Type @ in supported editable text, then choose a key from the Hidden values group.

If a hidden value might be missing, click the pipe token and add fallback text so the published form still reads naturally.

Captured hidden values appear as response columns. CSV exports include them, and Google Sheets workflows can use the same readable labels as the Responses table.

Fomr checks hidden value references when you publish. If form text references a hidden value key that is no longer declared, publishing shows an issue so you can fix it before respondents see the form.

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