Stainless vs GitBook vs Speakeasy: complete API docs and SDK generation platform comparison for January 2026
Blog post from Fern
API teams face challenges in balancing polished documentation with production-ready SDKs, as many platforms often require users to choose between these features or to integrate multiple tools that may fall out of sync. Stainless, GitBook, and Speakeasy each offer distinct solutions: Stainless focuses on automated SDK generation with early access documentation support, GitBook emphasizes collaborative documentation editing but lacks SDK generation and API testing, while Speakeasy pairs SDK generation with API design but needs separate tools for documentation. Fern provides a comprehensive approach by generating SDKs in nine languages with built-in REST, WebSocket, SSE, and gRPC support, offering a unified workflow for SDK and interactive documentation from a single API specification. The platforms vary in their support for CI/CD integration, self-hosting options, and protocol flexibility, with Fern standing out for its extensive language support, interactive API Explorer for testing, and self-hosted deployment capabilities, addressing compliance needs in regulated industries.