JSON Formatter & Validator
The JSON Formatter validates, beautifies and minifies JSON entirely in your browser. It reports the exact line and position of syntax errors, lets you choose indentation, and can compact JSON to a single line for transport. No data is ever sent to a server.
JSON is the lingua franca of APIs and config files, but a single misplaced comma or bracket makes it unparseable. This formatter validates your JSON, pinpoints the exact location of a syntax error, and re-indents it so nested structures are readable — or compacts it to a single line for transport.
How to use the JSON Formatter & Validator
- Paste your JSON into the editor.
- Read the validation result — errors show the exact line and position.
- Choose Beautify to indent it or Minify to compact it, then copy the output.
Common use cases
- Debug an API response that your code refuses to parse.
- Pretty-print a minified config file to read or edit it.
- Minify JSON before embedding it in a URL or environment variable.
Tips
- Valid JSON requires double quotes on keys and no trailing commas — a common source of errors.
- Everything is parsed in your browser, so you can safely format JSON containing private data.
Frequently asked questions
Is my JSON sent to a server? +
No. Validation, formatting and minifying all run locally in your browser, so you can safely format JSON that contains private data.
Why is my JSON invalid? +
The most common causes are trailing commas, single quotes instead of double quotes, or unquoted keys. The validator shows the exact line and position of the error.
What's the difference between beautify and minify? +
Beautify adds indentation and line breaks so the JSON is readable; minify strips all optional whitespace to make it as small as possible for transport.