Visibility Formulas & How to Use Them With Custom Fields

Visibility formulas let you keep your forms clean and relevant. Instead of showing every field to everyone, you can set a field to only appear when a certain selection is made. For example, a “Reason for repair” field can stay hidden until someone picks “Repair” from a drop-down list.

This article walks through the most common formulas, using the same field types and buttons you already see in FMX.

How to read a formula

Every formula points to a field and checks its value. In FMX, the field you reference goes inside {curly braces}. When the statement is true, the field appears; when it’s false, the field stays hidden.

Common formulas

When you need something to appear based on one selection

Use these when a field should appear after a single choice is made.

Checkbox — show the field when the box is checked:

Drop-down list — show the field when a specific option is chosen:

When something should appear even if multiple selections are made

For drop-down lists that allow more than one selection, use includes( ) to check whether a value is among the choices.

Either / or — appear when either option is selected:

Both required — appear only when both options are selected:

When a field should NOT show for a certain selection

Use != to hide a field when a particular resource is selected. This example hides the field whenever “Classroom” is the chosen resource:

Stuck on a complicated formula?

If you have a complicated visibility or value formula, let AI help. Open Google Gemini, paste in the [Copy AI Prompt] from your formula, and ask Gemini what specifications you need. It can help you check your logic and fill in the details.