LimeSurvey

LimeSurvey is a powerful, open-source survey platform and a free alternative to SurveyMonkey, Typeform, Qualtrics, and Google Forms. It builds unlimited surveys with dozens of question types, conditional logic, and multilingual support.

Responses can be analysed in-app with statistics and exported, and the platform supports tokens, invitations, and self-registration for respondent management. The Community Edition is fully self-hostable under the GPL.

With thousands of organisations relying on it for research and feedback, LimeSurvey is the de facto open-source survey tool.