Adding choice filters in XLSForm

Last updated: 25 Nov 2025

Choice filters create dynamic forms where options in one question depend on the answer to a previous question. This streamlines data collection by presenting only relevant choices, improving survey efficiency and accuracy.

Choice filters can be used for various applications, including:

• Hierarchical lists, such as continents and countries, where the list of countries depends on the selected continent (also known as cascading selects).

• Removing one or multiple options from a list if they are irrelevant for a respondent based on their previous answers.

• Reusing a list of options in XLSForm for multiple questions, where the list varies slightly from one question to the next.

• Reusing a list of options from a previous question, including only options that were selected by the respondent.

This article explains how to add choice filters in XLSForm and includes examples for different use cases. Choice filters are defined in the choice_filter column of the survey worksheet, and operationalized in the choices worksheet.

Note: This article focuses on adding choice filters in XLSForm. To learn about adding cascading select questions in the KoboToolbox Formbuilder, see Adding cascading select questions in the Formbuilder.

For hands-on practice with choice filters in XLSForm, see KoboToolbox Academy’s XLSForm Fundamentals Course.

Adding static choice filters

Static choice filters apply the same filtering conditions for all respondents. When using static choice filters, a list of options is filtered, but it does not vary based on previous responses. This can be useful when you want to reuse a list of options across multiple questions in your form with minor variations, without duplicating the choice list multiple times in your choices worksheet.

To add static choice filters in XLSForm:

1. Add a select_one or select_multiple question to your XLSForm and define your option choices in the choices worksheet.

2. In the choices worksheet, add a filter column.

   • You can name this column anything you choose (e.g., q2).

3. In the filter column, write any value (e.g., yes) next to the choice(s) you want to include in the choice list for your question.

   • This value will act as the filter. It can be any word or number.

4. In the survey worksheet, add a choice_filter column. This column will contain the choice filter expression used to filter the option choices.

   • The choice filter expression in its most basic form will take the format: filter = ‘value’.

   • For example, q2 = ‘yes’ will retain all choices with yes in the q2 column.

Example

In the example below, the same list of choices (activities) is used for two different questions. For the second question, the list is filtered to show only outdoor activities.

survey worksheet

type	name	label	choice_filter
select_one activities	activities	What activities do you enjoy doing in your free time?
select_one activities	outdoors_activities	Which of these outdoor activities are available in your city?	filter = ‘outdoors’
survey

choices worksheet

list_name	name	label	filter
activities	reading	Reading
activities	swimming	Swimming	outdoors
activities	running	Running	outdoors
activities	television	Watching television
activities	hiking	Hiking	outdoors
choices

Adding dynamic choice filters

Choice filters can also be used to filter a choice list based on a previous response. In this case, you will have a parent question with a corresponding parent list of choices, and a child question with a corresponding child list of choices. The choice list for the child question is filtered based on the response to the parent question.

For an example of an XLSForm using dynamic choice filters, see this sample form.

To add dynamic choice filters in XLSForm:

1. Add the parent and child question to your XLSForm and define their option choices in the choices worksheet.

   • These must be select_one or select_multiple questions.

2. In the choices worksheet, add a filter column.

   • It can be helpful to name this column the same as the parent question.

3. In the filter column, enter the name of the choice from the parent list that each option in the child list corresponds to.

4. In the survey worksheet, add a choice_filter column. This column will contain the choice filter expression used to filter the option choices.

   • If the parent question is select_one, the choice filter expression will be filter_column = ${question_name}, where question_name refers to the parent question.

   • If the parent question is select_multiple, the choice filter expression will be selected(${question_name}, filter_column).

When a respondent selects an option in the parent question, the choice list for the child question will be filtered to only include the corresponding choices.

Example

In the example below, continent is the parent question and country is the child question. The choice list for the country question will be filtered based on the response to the continent question.

survey worksheet

type	name	label	choice_filter
select_one continent	continent	Continent
select_one country	country	Country	continent = ${continent}
survey

choices worksheet

list_name	name	label	continent
continent	africa	Africa
continent	asia	Asia
country	malawi	Malawi	africa
country	zambia	Zambia	africa
country	india	India	asia
country	pakistan	Pakistan	asia
choices

Advanced choice filters in XLSForm

You can create more advanced choice filters by using logical operators, mathematical operators, functions, and regex in your choice filter expressions. This allows for highly customized and precise filtering of options, tailoring the form to specific data collection requirements and respondent characteristics.

Note: In advanced choice filter expressions, the name column of the choices worksheet can be used as a filter column.

Examples of advanced choice filter expressions in XLSForm include:

Choice filter	Description
selected(${parent_question}, name)	Display only responses that were selected in a previous parent_question.
filter = 'outdoors' and include = 'yes'	Combine choice filter expressions so both conditions must apply for the choice to be displayed.
name != 'none'	Exclude the None option from a choice list.
selected(${Q1}, name) or name='none'	Include choices selected in a previous question as well as a None option (even if not selected previously).
filter=${Q1} or name='other'	Include choices based on a previous question as well as an Other option.
filter=${Q1} or always_include='yes'	Include choices based on a previous question as well as a set of options that should always be included.
filter <= ${product_count}	Use numbers in the filter column instead of text, and filter based on a number from a previous question or calculation.
if(${relationship_status} = 'married', filter = 'married', filter = 'unmarried')	Use if-statements to conditionally display choices based on the respondent’s background.

To learn more about building form logic expressions in XLSForm, see Introduction to form logic in XLSForm.

Example

In the example below, the underlying choice list for Q1 and Q2 is the same, but only the options selected in Q1 will be displayed to respondents when answering Q2.

survey worksheet

type	name	label	choice_filter
select_multiple item	Q1	Which household items do you currently own?
select_multiple item	Q2	Which of these items would you consider upgrading in the future?	selected(${Q1}, name)
survey

choices worksheet

list_name	name	label
item	fridge	Refrigerator
item	tv	Television
item	fan	Ceiling fan
item	microwave	Microwave oven
item	radio	Radio
item	bike	Bicycle
item	phone	Mobile phone
item	laptop	Laptop computer
choices

In the resulting form, Q2 will display only the options chosen in Q1, as shown below.

Troubleshooting

Form slows or crashes with very long lists

Large choice lists which include thousands of rows may work in preview but fail when deployed. This happens because browser preview can handle large lists, while the mobile app or XLS parser cannot. To fix this, move large lists to an external CSV file and use select_from_file questions with choice filters. This approach is recommended for lists with more than 3,000 options.

Duplicate option names in a list

If your choice list includes duplicate option names (for example, if the same neighborhood name is present in different cities), enable choice duplicates in the settings worksheet by setting allow_choice_duplicates to yes.