Open Source Survey Software
Survey responses are unusually sensitive - they pair candid opinions with the PII of the person who gave them - yet hosted form tools both store that data on their servers and cap how many answers you can collect before charging more. The open source options here let you run the forms and keep every response on infrastructure you control, so honest answers never become a third party's dataset.

PostHog
Open source product analytics platform with session replay, feature flags, experiments, surveys, and data pipelines

Formbricks
Open source experience data hub for in-app, website, link, and email surveys

HeyForm
Open-source form builder for surveys, quizzes, polls, and conversational forms

LimeSurvey
Open-source survey platform for creating questionnaires, polls, and forms with branching and multilingual support

TDuck
Privatizable survey and form system with drag and drop design, analysis, and webhook sync

Nextcloud Forms
Self-hosted surveys and questionnaires for Nextcloud with CSV export and private responses

KoboToolbox
Survey data collection and management platform with an API for forms, reports, and exports

Concerto Platform
Open-source online adaptive testing platform for building and running assessments