Apidog

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.

Mintlify

Mintlify is a documentation platform that helps teams build and maintain product and API documentation that stays current automatically. It positions itself as a knowledge layer for both human readers and AI agents, offering an API playground, authentication-aware docs, and an MCP server so AI tools can query documentation directly. The platform is used by companies ranging from large enterprises like Microsoft and Anthropic to YC-backed startups, and reports serving tens of millions of documentation page views. Paid tiers add unlimited editor seats, automation features, preview deployments, and enterprise controls like SSO, SCIM, and RBAC.

Mockoon

Mockoon is a desktop and CLI tool for creating and running mock REST APIs locally, without needing a remote server or an account. It offers an intuitive interface for designing realistic mock endpoints, with support for dynamic templating, rules-based response matching, JSON databases, proxy mode, and OpenAPI specification compatibility. The core desktop application and CLI are free and open source, while Mockoon Cloud adds paid capabilities like real-time team collaboration, cloud-hosted mock deployments, and automatic data synchronization. It is used by frontend and full-stack developers, QA teams, and API designers, including in regulated industries that value its offline-first, privacy-focused design.

Postman

Postman is an API platform for building and using APIs. Postman simplifies each step of the API lifecycle and streamlines collaboration.

Hoppscotch

Hoppscotch is a lightweight, web‑based tool that lets developers design, test, and document APIs without leaving the browser. Its clean UI supports REST, GraphQL, WebSocket, and gRPC, making it a versatile companion for any API workflow. The platform is open‑source, free to use, and integrates seamlessly with GitHub, GitLab, and Bitbucket, allowing teams to version‑control collections and share environments effortlessly.

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.