JSONPlaceholder is a free, fake online REST API designed for prototyping, tutorials, and UI demos without standing up a real backend. It provides predictable endpoints for resources like posts, comments, albums, photos, todos, and users with realistic data shapes. Because the data is publicly available and stable, you can build fetch logic, paginate, and render lists while focusing on front-end patterns rather than server plumbing. The API accepts typical HTTP verbs and returns JSON in a consistent format, making it easy to swap with a real server later. It’s widely used in examples, workshops, and automated tests where a dependable dummy service accelerates iteration. With zero setup, it removes a major friction point for learning HTTP clients and front-end data flows.