Google Forms response validation blocks answers that do not match the format, length, number range, or selection count your question needs. The setting lives on each supported question, so you apply it one question at a time.
Start by choosing the right question type, then open More, turn on Response validation, and set the rule. Here are the current ways to use it in the Google Forms web editor and, when needed, Apps Script.
Start with a supported question type
Open your form in Google Forms and add or select the question you want to control. Response validation appears under More for Short answer, Paragraph, and Checkboxes. Multiple choice grid and Checkbox grid do not use that menu item; they have their own response rules, Require a response in each row and Limit to one response per column.
Choose Short answer for number rules, text rules, character limits, and regular expression rules. This is also where email-format validation appears when Google Forms offers it.
Choose Paragraph for longer written responses that need a minimum length, maximum length, or regular expression rule.
Use Checkboxes, Multiple choice grid, or Checkbox grid when the validation is about selection limits, required grid rows, or one response per column.
Add validation to a short answer
Use this method when the answer should be a number, a specific text format, a short code, an email-style entry, or a fixed character length. It is the standard path for Google Forms response validation on typed one-line answers.
Open the form, select the question, and set the question type to Short answer.
Click More, then choose Response validation.
Open the first rule dropdown and choose Number, Text, Length, or Regular expression.
Pick the matching rule. For numbers, choose the comparison or range rule you need.
For text, choose the text rule, including email-format validation when it appears.
For length, choose Maximum character count or Minimum character count.
For regular expressions, choose Contains, Doesn’t contain, Matches, or Doesn’t Match.
Enter the required number, range, text value, character count, or pattern.
Add Custom error text when you want the form to tell respondents exactly what to fix.
Set limits on paragraph answers
This fixes long-answer fields that are too short, too long, or missing a required text pattern.
Open your form and add or select a question.
Change the question type to Paragraph.
Click More, then select Response validation.
Use the first dropdown to choose Length or Regular expression.
For a length rule, choose Maximum character count or Minimum character count.
Enter the character count.
For a regular expression rule, choose Contains, Doesn’t contain, Matches, or Doesn’t Match.
Enter the pattern.
Add Custom error text if the default message is not clear enough for the people filling out your form.
Control how many checkboxes people select
The most common cause of checkbox problems is leaving the question unrestricted, which lets respondents choose too many or too few options.
Open the form and choose the checkbox question you want to control.
Set the question type to Checkboxes.
Click More and turn on Response validation.
Choose Select at least, Select at most, or Select exactly.
Enter the required number of boxes.
Add Custom error text to explain the limit in plain language, such as telling respondents to choose exactly two options.
Use validation in grid questions
Open your form and add a Multiple choice grid or Checkbox grid question.
Add the rows and columns you want respondents to see.
Turn on Require a response in each row when every row must be answered.
Open the bottom-right More menu and check Limit to one response per column when each column should be selected only once.
Use one-response-per-column rules carefully on grids where each column represents a unique ranking, slot, or assignment.
Remove response validation from a question
The most common cause of unwanted validation errors is an old rule left on a question after you changed what the question asks.
Open the form and select the question that is showing the validation error.
Click More, then choose Response validation again.
Because Response validation is a toggle menu item, selecting it again removes the validation controls and rule from that question.
Review the question by filling it out as a respondent would, especially if you changed the answer format after removing the rule.
Accept a suggested validation rule
Use this when Google Forms offers a response-validation suggestion for a question that clearly asks for a constrained answer, such as an email address or a number range. The suggestion appears automatically, so manual validation remains the reliable fallback.
Open or create a form in Google Forms and add a question that asks for a constrained answer.
When Forms suggests a response-validation rule, accept the suggestion.
After accepting it, open More and choose Response validation to review or edit the rule.
Use the manual Response validation menu when no suggestion appears or when the suggested rule does not match what you need.
Program validation with Apps Script
Apps Script can create native validation rules for supported Google Forms items, including TextItem, ParagraphTextItem, CheckboxItem, GridItem, and CheckboxGridItem.
Open the form and go to More, then Script editor. You can also open script.google.com and use FormApp.openById(formId).
Get or create the matching item type for the question you want to validate.
For short answers, use FormApp.createTextValidation() with the rule you need, such as number, whole number, text match, email, URL, or text length.
For paragraph answers, use FormApp.createParagraphTextValidation() with contains, does-not-contain, pattern match, pattern mismatch, or text length rules.
For checkboxes, use FormApp.createCheckboxValidation() with requireSelectAtLeast(number), requireSelectAtMost(number), or requireSelectExactly(number).
For grids, use FormApp.createGridValidation() or FormApp.createCheckboxGridValidation() with requireLimitOneResponsePerColumn().
Set the help text, build the validation, and apply it to the item with setValidation(validation).
Run the script and authorize it when prompted. If Apps Script is unavailable on a managed account, use the Google Forms web editor or ask your Google Workspace administrator about service access.
Know what validation cannot do
Native response validation stops invalid answers while the respondent is filling out the form. A script that reacts after a submission is different because it does not prevent the initial invalid submission.
Google Forms does not provide a consumer account-level switch that turns on response validation across every question in every form. Add the rule to each supported question that needs it.
There is no current Google-supported mobile app-only flow or download/install flow for adding response validation. If the option does not appear where expected, open the form in the Google Forms web editor and confirm that the question type supports validation.
Frequently Asked Questions
Can I add response validation to every Google Forms question type?
No. Google Forms offers the Response validation menu item on Short answer, Paragraph, and Checkboxes questions. Multiple choice grid and Checkbox grid questions have their own response rules instead: Require a response in each row and Limit to one response per column.
Can Google Forms validate an email address?
Yes. Use a Short answer question, open More, choose Response validation, select Text, then choose the email-format validation option when it appears.
Does custom error text replace the validation rule?
No. Custom error text only changes the message respondents see when their answer fails the rule. The selected validation rule still controls what the form accepts.
Can Apps Script stop invalid answers before submission?
Yes, when it creates native validation rules on supported form items. A script that only runs after submission does not stop the original invalid submission.
