I need a survey library that supports custom question types.

If you need a survey library with custom question types, here are the best options to look at:

Strong open-source choices

• SurveyJS
  Very flexible and one of the best-known options for custom question types.

  • Supports custom question types and custom widgets
  • Good for web apps
  • Has a form/survey designer
  • Works with React, Angular, Vue, and plain JS

• LimeSurvey
  Powerful survey platform with extensibility, though custom question types are more platform-oriented than library-oriented.

• Form.io
  More of a forms platform, but very extensible and supports custom components. Useful if your “survey” is really a form workflow.

If you want a library, not a platform

• SurveyJS is usually the first recommendation for custom question types.
• If you want maximum control and don’t mind building more yourself, react-jsonschema-form or Formik-based custom forms can work, but they’re not survey-specific.

What to verify before choosing

• Can you define new question schemas/types?
• Can the renderer be customized?
• Do you need drag-and-drop survey building?
• Does it support your framework: React/Vue/Angular/plain JS?
• Do you need branching logic, validation, piped text, or calculations?

If you want, I can narrow this down based on:

1. your frontend framework,
2. whether you want open-source only, and
3. whether you need a full survey builder or just the rendering library.