If you want to make sure that each respondent only takes your survey once, this little check is the one you need!
The feature checks the respondent ID and matches it with your respondent lists on our server. If a respondent returns for a second try, they will only see the Final screen of your survey.
Go to Extra Options to find the feature Unique Respondent and turn it on.
Click here for an explanation on how to make your respondent list.
Send out the survey URL to your respondents and include the UID of the specific respondent into each link. If your intro screen still contains the Name in the first custom field and the Email in the second custom field, and you have no third custom field you can add ?cf3=UID_123 to the URL. The 123 is the number of the respondent that will be variable. This is a guide that gives you more information about including information in the URL.
This feature is different from our feature “Unique Responses” because the check is done on our server instead of via a cookie, which means the check will also work on different browsers, devices and in incognito mode.
Mind that since the check is done on our server this feature won't be available in offline mode.