API Atlas vs apis.guru

Where apis.guru is the better choice

• + Ships actual OpenAPI documents, which is far more useful than prose if you are generating clients or mocks.
• + CC0 data with a clean, predictable JSON API.
• + Long-lived and widely consumed by codegen tooling.

Where it has limits

• − The interface is minimal and aimed at machines; there is very little editorial context around an entry.
• − Coverage is limited to providers that publish a formal OpenAPI spec, which excludes most of the ecosystem.
• − No MCP coverage.

Side by side

Cells reading “varies” or “not verified” mean we did not check it, and we would rather say so than guess. Check apis.guru’s own documentation for its current capabilities. We publish no figures for a competitor’s traffic, index size or revenue.

Which should you use?

• → Choose apis.guru if its strengths above match your task — ships actual OpenAPI documents, which is far more useful than prose if you are generating clients or mocks.
• → Choose API Atlas if you need to search APIs and MCP servers in one place, filter by what a record actually requires (authentication, CORS, free tier), and land on the provider’s own documentation — across 53 topics and 10,161 records.
• → Use both. Most of these tools are complementary; the catalogue is public and links out to everything it lists. There is no reason to pick one exclusively.