Spaceflight News vs The Guardian

Spaceflight News API is a free, keyless aggregator of space and astronomy news, articles, blogs, and reports pulled from NASA, ESA, and dozens of other spaceflight outlets, currently indexing more than 35,000 articles. The v4 API is fully open — no signup or API key needed — and returns paginated JSON with count/next/previous fields, plus a public OpenAPI/Swagger reference at its /v4/docs endpoint.

The Guardian's Open Platform serves the publication's own articles, tags, and section metadata across more than 1.9 million pieces of content, with a free Developer key limited to 1 call/second and 500 calls/day for non-commercial projects. A separate Commercial key removes those caps for a usage-based fee and adds images, audio, and video. Requests are authenticated with an API key and return JSON by default, with an XML format option available.