Validation & required fields
Configure per-field validation — required toggles, length and pattern rules, number ranges, and file constraints — so you collect clean, complete answers.
- Validation is per-field and configured in the field editor.
- A required toggle forces respondents to answer before they can submit.
- Text and textarea fields support minimum/maximum length and a regex pattern (advanced).
- Number fields support a minimum and maximum value; file fields support size, type, and count limits.
- Validation runs on the public form, and required fields are also enforced server-side when the submission is saved.
Validation keeps the answers you collect clean and complete. Rather than accepting anything, you set rules per field — this one is required, that one must be a valid length, this number must fall within a range — and the form checks each answer before it is accepted.
Every rule is configured in the field editor: select a field, open its validation section, and set the constraints that make sense for it.
Required fields
The simplest rule is the required toggle. When a field is required, respondents must answer it before they can submit the form. Required fields are validated on the public form and are also enforced server-side when the submission is saved, so a missing required answer cannot slip through.
Text length and pattern
Text and textarea fields can constrain what respondents type:
- Minimum length — reject answers shorter than a set number of characters.
- Maximum length — cap answers at a set number of characters.
- Pattern (advanced) — a regular expression the answer must match, useful for things like postal codes, reference numbers, or a specific format.
Number ranges
Number fields accept a minimum value and a maximum value, so an answer must fall within the range you allow — handy for quantities, ages, or ratings where only certain numbers make sense.
File constraints
File fields have their own set of limits so you receive uploads you can actually use:
- Maximum file size — capped per file, with a default of 10 MB.
- Allowed file types — an allowlist of extensions, so only the formats you expect are accepted.
- Minimum and maximum number of files — control how many files a respondent can (or must) attach.
For more on gathering documents and images, see collect file uploads.
How to configure validation
- 1In the editor, select the field you want to validate to open the field editor.
- 2Open its validation section.
- 3Set the rules that apply — the required toggle, length or pattern, number range, or file constraints.
- 4Preview the form and try an invalid answer to confirm the rule behaves as expected.
Frequently asked questions
Where do I set validation rules?
Is validation enforced only in the browser?
Can I require a specific format, like a postal code?
What is the default maximum file size?
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