Cataas vs Dogs

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.

The Dog CEO API serves random and breed-filtered dog images sourced from the Stanford Dogs Dataset plus community submissions, returning a direct image URL as JSON rather than the binary file itself. A live call to its breed list returns 108 main breeds and 99 named sub-breeds (42 of the mains have sub-breeds), giving 207 callable breed image paths across 165 leaf-level breed collections, each queryable via dedicated endpoints (e.g. /breed/hound/images/random), and it needs no signup or API key. The project is open-source with no pricing tier of any kind; hosting is covered by on-site ads plus voluntary PayPal donations.