DummyJSON vs Faker.js

DummyJSON is a free hosted REST API that supplies fake JSON data for frontend development, building, and testing without backend setup. Its listed resources include products, carts, users, posts, comments, quotes, todos, recipes, images, and authentication. Requests can use limit, skip, and select parameters; a limit of zero returns all items. A delay parameter simulates responses from 0 to 5000 milliseconds. Developers can create a hosted mock endpoint with their own JSON response and select GET, POST, PUT, PATCH, or DELETE. These endpoints last 90 days and accept response bodies up to 300 KB. The webhook inspector captures incoming requests for debugging and supports all HTTP methods; endpoints remain live for 24 hours, store up to 100 requests, and accept payloads up to 300 KB. Authorization, cookie, and x-api-key headers are removed before storage. Additional tools include a TOTP generator for base32 secrets and otpauth URIs, plus authentication examples for login, access and refresh tokens, and authenticated resource access. Product changes simulate requests but do not alter stored server data.

Faker.js is a free JavaScript library for generating synthetic data that resembles realistic information during testing and development. Its modules produce person, location, date, finance, commerce, and other data. Documented uses include unit tests, performance tests, demos, and development before a backend is complete. Pre-built instances cover more than 70 locales, and custom locales can be created. The implementation runs in browsers and Node.js; Faker v10 requires Node.js 20 or newer. Installation guidance covers npm, pnpm, yarn, and Deno, with examples for Vitest, Jest, Cypress, and Playwright. A seed can make generated values repeatable, although identical seeds may produce different results between Faker versions. The full package exceeds 5 MiB when minified, and its guide advises against deploying the entire package in a web app. Locale coverage varies, with some combinations using English fallback data or lacking applicable data. Faker is MIT licensed for commercial and non-commercial use and is self-hosted.