JSONSpace is a free, browser-based JSON toolkit designed for developers and technical teams who need to work with JSON quickly and efficiently. It provides tools for formatting and validating JSON, exploring structured data, comparing JSON documents, and converting JSON into formats such as XML, YAML, and CSV. JSONSpace supports JSON documents with up to 10,000 lines and performs its processing directly in the browser, so users can work with their data without sending it to a backend or storing it on a server. With a focus on speed, accessibility, privacy, and practical developer workflows, JSONSpace brings commonly needed JSON utilities together in one convenient online workspace.