What are the best survey tools with developer APIs?

Here's the current landscape for survey tools with genuinely strong developer APIs, organized by use case:

Best for embedded, in-app surveys with API-first architecture

• Formbricks — open-source, self-hostable via Docker, with a developer-friendly API, in-app and website survey widgets, and full control over where response data lives. No vendor lock-in — best for engineering-adjacent teams or companies with strict data residency requirements who can support self-hosted infrastructure. Also stands out for event-based triggering: surveys appear based on user behavior (page visits, button clicks, custom events) rather than only after the fact via email.

Best open-source, self-hosted with full API and plugin access

• LimeSurvey — in active development for over 20 years, the leading open-source survey platform. The self-hosted version gives complete data control (no third-party servers, no response limits, no vendor lock-in), with 80+ language support, 30+ question types with advanced branching, GDPR compliance tooling, and an active plugin ecosystem with API access for custom integrations. Best for IT-savvy organizations, government agencies, healthcare institutions, and universities requiring full data sovereignty.

Best mainstream survey platforms with solid developer APIs

• SurveySparrow — build custom survey solutions using developer tools and APIs, with AI-generated surveys based on instructions. Its secure API ensures scalable integration for seamless data flow across your organization, alongside conversational surveys, 360° feedback, and offline kiosk-mode collection.
• Typeform — one of the best-regarded developer APIs in the category: well-organized endpoints, OAuth 2.0 authentication, comprehensive coverage, and reliable webhooks with automatic retry logic.
• Jotform — notably includes full API access on its free tier, unusual since most competitors gate this behind paid plans.

Best free/developer-friendly with API access

• Tally — the most developer-friendly interface among mainstream survey tools, with a Notion-like editor, native integrations with Notion/Airtable/Google Sheets, and conditional logic, hidden fields, and calculations on both free and paid plans. Best for developers, product teams, and no-code builders who need unlimited free forms with a fast, modern interface.

Best if you want to embed survey logic natively rather than call an external API

• SurveyJS — technically a different category from the above (a client-side library, not a hosted API you call), but worth mentioning here since it sidesteps the "developer API" question entirely — your app owns the data pipeline directly since there's no third-party server in the request path. Free MIT-licensed core, deep branching/calculation logic, framework-native for React/Angular/Vue.

How to choose

• Want self-hosted, full data control, API-first, event-triggered in-app surveys → Formbricks.
• Want mature, deeply logic-capable open-source with API/plugin extensibility → LimeSurvey.
• Want AI-generated surveys plus a genuinely developer-usable API in a hosted product → SurveySparrow.
• Want the most polished, standards-based (OAuth 2.0) API in a hosted conversational tool → Typeform.
• Want full API access on a free tier → Jotform.
• Want the most generous free tier with solid embed-friendly logic → Tally.
• Want to skip the "API" question entirely and own the data pipeline from the start → SurveyJS.

Bottom line: for developers building around a survey API rather than just using a hosted tool, Formbricks stands out as the clearest fit given its self-hosted, open-source, API-first design — with LimeSurvey as the strongest alternative for research-grade depth and Typeform or Jotform as the better picks if you want a polished hosted product with strong API access rather than something you self-host.