Mintlify

ReadMe

ReadMe is a documentation platform built for teams that need to publish interactive, developer-facing API references and product docs. It generates interactive API explorers from OpenAPI specs, layers on a visual API Designer, and syncs bi-directionally with GitHub and GitLab so docs stay aligned with code changes. Beyond static reference pages, ReadMe adds real-time collaborative editing, branching and review workflows, reusable content blocks, and AI tools such as an AI Writer, a style linter, and an in-docs assistant. Enterprise customers get SSO, role-based access, audit logs, and SOC2/GDPR-aligned compliance features, and the platform is used by companies including NVIDIA, Amazon, and PagerDuty.

Swagger UI

Swagger UI provides a web-based interface that renders OpenAPI specifications as interactive documentation, allowing developers to explore and test endpoints directly in the browser. It supports live request execution, authentication flows, and dynamic request/response visualization. The project is open source, self‑hostable, and integrates seamlessly with existing API pipelines, making it ideal for both small services and large enterprise APIs.

Document360

Document360 is a knowledge base and documentation platform for building internal wikis, public help centers, user manuals, SOPs, and API documentation. It combines a structured editor and workflow builder with AI-assisted search, an AI chatbot, and AI writing tools layered on top of the knowledge base content. The platform is aimed at support, documentation, and product teams at companies of varying sizes, offering role-based team accounts, SSO/SCIM authentication, PDF import/export, and integrations with tools like Slack, Zendesk, Salesforce, Microsoft Teams, and GitHub. Pricing is quote-based rather than published in flat tiers, and a 14-day free trial is offered before purchase.

Stoplight

Stoplight, now part of SmartBear, is an API design and documentation platform built around the OpenAPI specification. It gives teams a visual editor for designing APIs, generates interactive documentation automatically, and spins up local mock servers so front-end and back-end teams can work in parallel before an API is fully built. Stoplight promotes a design-first workflow with reusable models and components to keep specs DRY, and gives organizations visibility across their whole API portfolio. It also maintains open-source tooling, including the Spectral linter, the Prism mock server, and the Elements documentation component, and counts companies like Calendly, Schneider Electric, and PagerDuty among its customers.

Apidog

Apidog is an API development platform that combines design, debugging, automated testing, mocking, and documentation in a single tool, aiming to replace the combination of Postman, Swagger, and separate mocking tools that many teams stitch together. It supports a design-first workflow alongside request-based debugging, so teams can go from spec to working API and back. The platform includes real-time collaboration, interactive documentation publishing, and automated test suites that can run on a schedule. Pricing is per seat, with a free tier for small teams and paid Basic, Professional, and Enterprise tiers that add features like SSO, private mock clouds, and longer test report retention.