JSONPlaceholder vs TotalShiftLeft Sandbox

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.

TotalShiftLeft's Sandbox (self-titled "API Learning Sandbox") is a free hands-on playground for practicing REST, GraphQL, and SOAP against the same underlying data store — a session is auto-created on first request (no signup) and seeded with demo users, products, and orders that expire after 30 minutes. Beyond plain access, it supports three optional auth flows for testing auth code paths: an x-api-key header, a JWT obtained from POST /auth/token, and an OAuth2 client-credentials exchange at POST /auth/oauth. Query params let callers simulate real-world conditions — added latency, forced error codes, or random failures — making it a fixture for testing API client resilience rather than just CRUD happy paths.