Excel data validation drop-down list

Introduction

Data validation is a feature in Excel used to control what a user can enter into a cell. For example, you could use data validation to make sure a value is a number between 1 and 6, make sure a date occurs in the next 30 days, or make sure a text entry is less than 25 characters.

Data validation can simply display a message to a user telling them what is allowed as shown below:

Data validation can also stop invalid user input.

For example, if a product code fails validation, you can display a message like this:

In addition, data validation can be used to present the user with a predefined choice in a dropdown menu:

This can be a convenient way to give a user exactly the values that meet requirements.

Data validation controls

Data validation is implemented via rules defined in Excel's user interface on the Data tab of the ribbon.

Important limitation

It is important to understand that data validation can be easily defeated.