Custom Variables

Overview of using custom variables

How can I pass in additional information to the survey?

You can pass in additional information in the survey using Custom Variables.

What are Custom Variables and where are they stored?

Custom Variables are special variables used to store additional information that is to be used in the survey. Custom Variables used in the survey are stored with the respondents’ responses. You can view the Custom Variables online using the Response Viewer. Custom Variables are also available in the Excel and CSV Raw Data downloads. You can also analyze your data based on Custom Variables.

To track e-mail addresses and Custom Variables please use the Respondent Tracking link when sending emails via the QuestionPro email system.

What are the limits on Custom Variables?

  • You can upload up to 255 custom variables.
  • Each Custom Variable can store up to 128 characters.
  • You cannot use a Comma (,) or the Pound/Hash (#) sign in the Custom Variables.

Note: If you are passing the Custom Variables / External Reference Variable via the URL, please limit your use to alphanumeric characters (A to Z, a to z, 0 to 9). Avoid use of special characters: space (” “), pound/hash (“#”), ampersand (“&”), percent (“%”), question mark (“?”), etc.

How can I set up custom variables?

When using QuestionPro email management tool, you can upload Custom Variables with each respondents email address.

If you are not using QuestionPro email management tool for distribution, then you can pass in Custom Variables along with the survey URL. Following is the format for routing in the Custom Variables: after the URL (page name), we use question mark ( ? ) to start the variable data pair and we separate each variable data pair with one ampersand ( & ) mark..

Example Survey URL:

Custom Variables are included as follows:

Do Custom Variables support multilingual characters?

Yes, you can upload multilingual characters as Custom Variables. Limited special characters are also supported.

Where in the survey can I use Custom Variables?

Custom Variables can be used in questions, answer options, thank you page, and in the email invitation.

How can I use Custom Variables?

To display the Custom Variables on the survey, email invitation, or thank you page, you can use the following tags for the corresponding Custom Variables:

  • Custom Variable 1: ${custom1}
  • Custom Variable 2: ${custom2}
  • Custom Variable 3: ${custom3}
  • Custom Variable 4: ${custom4}
  • Custom Variable 5: ${custom5}
  • Custom Variable N: ${customN}

You can also prepopulate the open-ended text type question on the survey.

Can the Custom Variables be used for analysis?

Yes. You can set up Grouping based on the Custom Variables. For example, if you have uploaded “Department” as a Custom Variable, you can set up Groups for each and run analysis separately for each Department.

What is the External Reference Variable?

External Reference Variable is an another variable which can be used to pass in data to the Survey. The External Reference variable (such as ext_ref) is used to associate responses to their respondents. You can assign an ID number or anything else that will uniquely identify a respondent to the ext_ref variable. When the results are collected, the ext_ref variable is captured and stored with the other data.

How can I use the ext_ref variable with my own email program?

Every survey that you create will have a unique URL. To include other data to be captured along with the survey data you just need to add the ext_ref parameter to the URL. For example:

Replace xxxx with your unique id for the respondent.

I am using a customized URL. How can I pass the ext_ref variable in the customized URL?

The ext_ref parameter can be passed along with the URL by appending the suffix “?ext_ref=xxxx” to the URL as shown in the following example.

The ext_ref tag is appended as follows:

Are there any limitations to the ext_ref variable?

  • The External Reference Variable can store up to 64 characters.
  • You can use alphanumeric characters (A to Z, a to z, 0 to 9).
  • Accented characters or characters from languages other than English may not get saved. Please limit the character use to English.
  • You cannot use the pound/hash [#] in the External Reference Variable.
  • We recommend you not use commas and quotation marks (single or double) in the ext_ref variable.

How can I use the ext_ref with the QuestionPro Email List Manager?

If you are using the email list management interface to send out email, add the following tags to your survey invitation:


The &ext_ref variable is automatically captured in the raw response data.

Note: The mail merge tags are special variables that are used in Email List Management in tracking the email addresses of respondents. Simply append the &ext_ref=xxxx to the end of the mail merge tags.

License & Access Options
This feature/tools described here are available with the following license(s) :

  • Corporate Edition: 
    • Unlimited Surveys, Questions, Responses
    • Advanced Toolset and Features
    • No Long Term Commitment