> For the complete documentation index, see [llms.txt](https://docs.acho.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.acho.io/app-builder/app-construction/elements/form-check.md).

# Form Check

Form elements have a Form Check section to validate user inputs.

By default, it comes with a validator for required fields. By toggling Required, you can require the user to enter an input. If no input is entered, the error prompt will be shown.

![](https://3574406564-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MB_fx7PCUqvFEdrucJC%2Fuploads%2FOe5eT5Iiyrd2Kgh83s0t%2Fimage.png?alt=media\&token=879de4ce-07f6-4f32-8225-b60bf7025fc3)

You can also add validators, such as checking if the input is an email.

![](https://3574406564-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MB_fx7PCUqvFEdrucJC%2Fuploads%2FjDH6Wn5yKWaVmXtVyhxT%2Fimage.png?alt=media\&token=ba173199-0fd5-4231-b059-ab61ec40e6fd)

Select the check type. When Check Value is toggled on, the validator will be on. Type in what text to display when there's an error into Error prompt.