Mockaroo - A realistic data generator to test your app

Monokai JSON+ - Sublime Monokai Theme for JSON.

JSON Generator - Create mock and sample JSON using a powerful template syntax

Editor.js - A block-styled editor with clean JSON output

Softbuilder SB Data Generator - SB Data Generator is a simple and powerful tool to generate and populate selected tables or entire databases with realistic test data.

Power JSON Editor - Power JSON Editor is a JSON editor for developers with Visual Tree View and multiple plugins like Array Table Editor and jq Processor, also with format converter plugins, it is easy to convert files between JSON, PLIST, YAML and TOML.