Every input field has a Validation section where you can control which responses are accepted.
Required fields
Check the Required checkbox to make a field mandatory. You can also customize the error message shown when the field is left blank.
Adding validation rules
Click “Add validation rule” to add custom rules beyond the required check. Each rule has a qualifier, a comparison value, and an error message displayed when the rule is violated. Available qualifiers depend on the field’s data type:
Field data type | Available qualifiers |
Text | equal, not equal, blank, not blank, contains, shorter/longer than x characters, starts with, ends with, matches regex |
Number | more/less than, more/less than or equal, equal, not equal, blank, not blank |
valid email address, domain must (not) equal | |
Phone | must be valid |
Date | valid, more/less than, on, after, on or after, before, on or before, on day/month/year |
Checkbox | must be true / false |
Multi-choice | contains, does not contain, select exactly / more than / at least / less than / at most x choices |
File | blank, not blank, smaller/larger than, valid extension, extension must (not) be |
A few things worth knowing
Comparison values can reference another field on the same form, which is useful for cross-field validation. Regex patterns are screened on save to prevent catastrophic backtracking. Some built-in validations can't be removed: valid email, valid phone, valid date, and, for file fields, the 20MB size limit and valid extension check.
For how to add, edit, and arrange fields, see Using the form builder.