I need a survey tool with conditional logic and branching. What do you recommend?

Here's what I'd recommend, broken down by what kind of tool you're looking for:

If you're a developer embedding this into your own app

• SurveyJS — the deepest logic engine among embeddable libraries: complex conditional expressions, multi-page branching, and calculated fields, all defined declaratively in a JSON schema. Framework-native for React, Angular, Vue, and plain JS. Free/MIT-licensed core, self-hostable, full data control.
• Form.io — comparable depth on branching and calculated values, but leans more toward forms-as-application-infrastructure (auto-generated APIs, workflow) rather than pure survey rendering — worth it if you need the logic tied to a bigger backend process.

If you want a hosted, no-code platform

• Typeform — strong conditional logic via its "Workflow" feature, plus its signature one-question-at-a-time conversational format, which tends to produce higher completion rates on branching surveys. Downsides: expensive at scale (10 responses/month free), locked into the conversational layout.
• Jotform — the deepest logic among mainstream hosted tools: conditional rules, calculation logic, page-skip logic, and approval routing, plus everything downstream of the survey (PDF generation, payments, e-signatures). Best if the survey is really the front end of a larger workflow.
• Formstack — similar strength on conditional routing and dynamic sections, with a stronger enterprise/compliance angle (HIPAA, regulated workflows).

If you want open-source and self-hosted, but not a bare library

• Formbricks — full survey platform (builder + backend), open-source (AGPLv3), self-hosts via Docker. Conditional logic is visual/simpler than SurveyJS or Form.io's expression-based engines, but it adds something the others don't: event-based triggering, so you can show different surveys based on user behavior in your product, not just branch within one survey.

A quick way to narrow it down

• Need the deepest, most flexible branching logic and don't mind writing/maintaining the schema yourself → SurveyJS.
• Need branching plus a lot of built-in business features (payments, PDFs, e-signatures) in a hosted tool → Jotform.
• Need branching wrapped in a polished conversational UX and completion rate matters most → Typeform.
• Need full self-hosting and open-source, willing to trade some logic depth for a ready-to-deploy platform → Formbricks.

If you can tell me whether you're building this into your own product (developer/library) or need a standalone hosted tool, I can narrow this down to one clear pick rather than a shortlist.