10 Best Stoplight Alternatives & Competitors (2026)

Mintlify is a modern documentation platform focused on beautiful, auto-generated API docs from OpenAPI specs with strong search and component support. It offers fast setup and clean themes but lacks ReadMe's deep bi-directional GitLab sync, AI branch reviews, and built-in MCP server creation. Pricing is subscription-based with fewer enterprise controls than ReadMe's versioned workflows.

Postman provides API development, testing, and documentation tools with a large user base and built-in API explorer. While excellent for API-first teams, it emphasizes collections over polished long-form guides and offers weaker AI writing assistance and changelog features compared to ReadMe's integrated documentation stack.

GitBook is a collaborative docs platform with Git sync and strong publishing features. It supports Markdown well but trails ReadMe in interactive API references, AI linter enforcement, and developer usage analytics, making it better suited for general product docs than API-heavy use cases.

Docusaurus is an open-source static site generator popular for technical documentation with MDX support. It requires more custom development for API explorers and lacks ReadMe's hosted AI tools, branch reviews, and bi-directional enterprise Git sync out of the box.

Slate is a lightweight open-source API documentation generator with clean layouts. It requires manual maintenance and offers no AI assistance, hosting features, or Git sync, making it far less feature-complete than ReadMe for growing teams.

Redoc delivers fast, interactive API reference rendering from OpenAPI files with minimal setup. It excels at reference docs but lacks ReadMe's full guides, discussions, AI linter, version control, and usage analytics features.

Swagger UI is the widely used open-source tool for rendering interactive API documentation from OpenAPI specs. It is free and simple but provides none of ReadMe's AI writing tools, Git sync, themes, or changelog and discussion capabilities.

Apiary specializes in API blueprint and mock server creation with documentation hosting. It has limited modern AI features and weaker Git integration compared to ReadMe's comprehensive documentation platform and enterprise sync options.