Structured data
JSON Formatter
Format, validate, and minify JSON data with error highlighting.
About JSON Formatter
The JSON Formatter is an all-in-one validator and beautifier for JavaScript Object Notation. It helps you prettify JSON responses from APIs, making them readable, or minify them for compact storage and transmission.
Debug your API payload structures faster. Raw JSON is often single-lined and hard to read; this tool formats it with proper indentation and nesting. It also catches syntax errors, such as missing quotes or trailing commas, which are common sources of application failures.
Paste your raw JSON string into the editor. The tool automatically formats it. If there is an error, it highlights the specific line number. You can toggle between "Pretty" and "Minified" views to suit your needs.
Under the Hood
JSON parsing uses the native `JSON.parse` with a try-catch block to capture specific syntax errors (like trailing commas or unquoted keys). Formatting relies on `JSON.stringify(obj, null, indentation)`. For the editor experience, we use `CodeMirror` (or similar text area logic) to provide line numbers and basic syntax highlighting, making it easier to spot nesting errors in large payloads.