HTTP Dog vs RandomDuck

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.

Random-d.uk's /random endpoint returns a JSON object linking to a random duck photo or GIF, with a type query parameter to request JPG or GIF specifically. A companion /randomimg endpoint serves the image file directly instead of the JSON wrapper, and the service also accepts community-submitted duck photos.