Mockaroo - A realistic data generator to test your app

ReqRes - A hosted REST-API ready to respond to your AJAX requests.

DUMMY DATABASE - Generate and manage synthetic datasets easily with DUMMY DATABASE

Insomnia REST - Design, debug, test, and mock APIs locally, on Git, or cloud. Build better APIs collaboratively for the most popular protocols with a dev‑friendly UI, built-in automation, and an extensible plugin ecosystem.

Random Data Monster - Random Data Monster is a comprehensive suite of advanced random data generation that features generating secure passwords, names, numbers and more than 30+ Google Sheets custom functions to generate random data.

Appbase.io - Search stack for building modern apps