Required fields and validation

Control which questions are mandatory and how answers are validated.

Making a field required

Toggle the Required switch on any block to make it mandatory. Required fields show a red asterisk (*) next to the question. The form cannot be submitted until all required fields are filled in.

Built-in validation

Some block types have automatic validation:

• Email — Must be a valid email format (e.g. user@example.com)
• Phone — Must contain only digits, spaces, dashes, parentheses, and the + symbol
• File Upload — Enforces the 5MB size limit and allowed file types (PDF, DOC, DOCX, PNG, JPG, JPEG, GIF, WEBP)
• Rating — Must select a value if required

Validation errors

When a respondent tries to submit with invalid or missing fields:

1. The form scrolls to the first error
2. Invalid fields are highlighted with a red border
3. An error message appears below each invalid field explaining what's wrong
4. The submit button shows a loading state, then returns to normal

Tips

• Mark the most important fields as required, but don't overdo it — requiring every field can frustrate respondents
• Use block descriptions to explain what format you expect (e.g. "Enter your phone number including country code")
• Email validation only checks format, not whether the address actually exists