JSONPlaceholder vs RoboHash

JSONPlaceholder is one of the longest-running free fake REST APIs, serving a fixed set of 100 posts, 500 comments, 10 users, 100 albums, 5,000 photos, and 200 todos as JSON. Every standard verb works against each resource, including nested routes like /posts/1/comments, though POST/PUT/PATCH/DELETE only simulate a write and return a fake response without persisting any change. Its data and IDs never change, which is exactly why it's the default backend in countless framework tutorials and testing guides.

RoboHash turns any string — an email address, IP, username, or filename — into a deterministic robot, monster, human, or cat avatar, so the same input always renders the same image. Six selectable sets (robots, monsters, robot heads, cats, human avatars, gorillas) each support size, background (bgset), and Gravatar-based seeding, and images are served directly from the URL by file extension in PNG, JPG, GIF, or BMP. No signup, key, or request body is required, and outputs are freely embeddable under a CC-BY license.