What should I use to create docs for a public API?

For a public API, the best choice is usually a docs site generated from an OpenAPI spec.

Recommended approach

• Define your API with OpenAPI (Swagger)
• Use a docs generator/viewer like:
  • Redoc / Redocly – polished, readable, great for public-facing docs
  • Swagger UI – interactive and widely supported
  • Stoplight – good for design + docs + collaboration
  • GitBook / Docusaurus / MkDocs – if you want more control and narrative guides alongside reference docs

Best default pick

If you want a solid, modern, public API documentation setup:

• OpenAPI + Redoc
• Add:
  • authentication examples
  • endpoint examples
  • error code reference
  • pagination/filtering docs
  • quickstart guides

If you want different strengths

• Fastest to ship: Swagger UI
• Best-looking API reference: Redoc
• Best for docs + tutorials + versioned content: Docusaurus or GitBook
• Best for API-first workflows: Stoplight

My practical recommendation

If this is a real public API, use:

1. OpenAPI as the source of truth
2. Redoc for the reference docs
3. Docusaurus or GitBook for guides/tutorials

If you tell me your stack (language/framework) and whether you want reference docs only or full developer portal, I can suggest the best specific toolchain.