Data validation in Google Sheets is a feature that ensures data consistency and accuracy by setting rules for acceptable entries, improving data integrity, and reducing errors.
- Restrict input to specific types like numbers, text, or dates.
- Automatically flag incorrect data entries with customizable error messages.
- Ensure users enter valid information based on set criteria.
- Apply rules across ranges to streamline data input processes.
Types of data validation
Google Sheets offers powerful data validation features to ensure users input accurate and consistent data into cells. Here are the main types of data validation you can use in Google Sheets:
Custom Formula
- Validates data based on a custom formula.
- Example: Allow only even numbers using =MOD(A1,2)=0.

Number Validation
- Validates data to ensure only numbers are entered based on conditions like greater than or within a range.
- Example: Allow numbers greater than 500.

Text Validation
- Validates text input based on conditions like specific keywords or length restrictions.
- Example: Restrict text length to under 20 characters.

Date Validation
- Ensures only dates within a specific range are entered.
- Example: Allow only dates after 2024-01-01.

2.5. List Validation
- Creates a dropdown list with predefined options for selection.
- Example: Choose from regions like North, South, East, or West.

2.6. Checkbox Validation
- Adds checkboxes to restrict data to TRUE/FALSE values.
- Example: Use checkboxes for task completion status.

3. How to Use Data Validation in Google Sheets
Data validation in Google Sheets helps ensure that the data entered into a cell meets specific criteria, reducing errors and maintaining consistency. Here's how to apply data validation:
Step 1: Select the Range for Data Validation
First, select the cells or range where you want to apply data validation. For example, if you want to limit entries in the "Sales Amount" column, select the relevant cells in that column.

Step 2: Open the Data Validation Menu
- Go to the Data menu at the top of Google Sheets.
- Click Data validation from the dropdown menu.

Step 3: Set Criteria for Data Validation
In the Data validation dialog box, you can set the criteria for the selected range. You can choose from various types of validation rules, such as:
- List of items: Allow only entries from a predefined list (e.g., "North," "South," "East").
- Number: Restrict entries to numeric values, with options for greater than, less than, equal to, or between certain numbers.
- Text: Limit text to certain conditions like length, contains, or starts with specific characters.
- Date: Ensure only valid dates are entered.
- Custom formula: Use a custom formula for more complex validation (e.g., =A1>0 for only positive numbers).

Step 4: Apply the Data Validation
Once you’ve set your criteria, click Done to apply the data validation.

Step 5: Test the Validation
Now, try entering data into the validated cells. If you attempt to enter invalid data (e.g., a number when only text is allowed), you’ll see an error message, and Google Sheets will prevent the invalid entry.
