JSON Formatter
Format, validate, and beautify JSON instantly.
JSON (JavaScript Object Notation) is the default data format for web APIs, configuration files and logs, but machine-generated JSON usually arrives as one unreadable line.
About JSON Formatter
Paste minified or malformed JSON and instantly get a validated, beautifully indented output with clear syntax highlighting and error line numbers. This JSON formatter and validator is built for developers debugging API responses, config files, or log payloads, and doubles as a JSON minifier when you need a compact version for production.
JSON (JavaScript Object Notation) is the default data format for web APIs, configuration files and logs, but machine-generated JSON usually arrives as one unreadable line. This online JSON formatter parses your input, reports the exact position of any syntax error, and re-prints it with clean indentation so you can scan keys, nesting and arrays at a glance. Because parsing happens in your browser, you can safely paste API responses that contain tokens or customer data.
How to use JSON Formatter
- Paste your raw or minified JSON into the input box.
- Choose an indentation size — 2 spaces, 4 spaces or tabs.
- Read the formatted result on the right, or fix the highlighted error if the JSON is invalid.
- Copy the output or download it as a .json file.
Key features
- Instant validation with a clear error message when JSON is malformed.
- Adjustable indentation to match your project's style guide.
- Handles large payloads without sending anything to a server.
- One-click copy and download of the formatted result.
Common use cases
- Reading a minified API response while debugging a request in the browser or Postman.
- Cleaning up package.json, tsconfig or other config files before committing them.
- Checking that a hand-edited JSON fixture is valid before loading it into tests.