When should I use JSON stringify?

Use JSON.stringify() whenever you need to convert JavaScript objects to JSON strings for transmission, storage, or logging. Common use cases include sending data to APIs through HTTP requests, storing objects in localStorage or sessionStorage, logging objects for debugging (more readable than [object Object]), saving configuration data to files, and transmitting data between web workers or iframes. Use it when you need to compare objects by value rather than reference, as stringified objects can be directly compared. Stringify is essential before sending data with fetch() or XMLHttpRequest to APIs expecting JSON. You also need it when saving application state or persisting data between sessions. Do not use stringify for simple string concatenation or when objects already contain methods you want to preserve. Use our JSON Formatter at jsonconsole.com/json-formatter to preview stringify output and ensure your data serializes correctly before using it.