JSON (JavaScript Object Notation) is the standard data-interchange format for APIs and web services. However, raw JSON sent from a server is usually minified—squashed into a single line to save bandwidth. While this is great for computers, it makes it incredibly difficult for developers to read, debug, or edit.
Our free online JSON Formatter solves this by instantly parsing your raw JSON string and outputting it with clean, readable indentation. Simply paste your data into the input box and click "Format JSON". It will apply standard 2-space indentation to make nested arrays and objects perfectly legible.
Additionally, this tool acts as a strict JSON Validator. If you are missing a comma, forgot to quote a key (a common mistake), or have trailing commas, the native parser will instantly catch the syntax error. We intercept that error and display exactly why your JSON is invalid, allowing you to quickly spot and fix the bug.
Best of all, this tool runs entirely locally in your browser. We never upload your payloads to a server, ensuring your sensitive configuration files, API responses, or proprietary data remain strictly private and secure.