Cataas vs HTTP Dog

Cataas ("Cat as a Service") is a free, open-source REST API that returns random cat images and animated GIFs, filterable by tag, with options to overlay custom text or crop a specific position. A JSON mode (?json=true) returns the image's metadata — id, tags, and direct URL — instead of the binary file itself. It's maintained on GitHub under the cataas org with no signup or pricing tier; a Donate link is the site's only monetization.

http.dog serves a themed dog photo for most standard HTTP status codes (e.g. GET /200, /404, /451), following the same status-code-as-image idea as http.cat. A .json variant returns direct links to the same image in JPEG, WebP, AVIF, and JXL instead of the image itself. It's a static Cloudflare-fronted site with no server-side application logic, so there's no API key, authentication, or rate limit of any kind.