JSON Formatter
Format, beautify, validate and minify JSON. Instant syntax error detection with line numbers.
About the JSON Formatter
This JSON formatter runs entirely in your browser. Paste any JSON into the input box, then choose Format to beautify it, Minify to compress it, or Validate to check for syntax errors. Nothing is uploaded — all parsing happens locally with JavaScript's built-in JSON.parse.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight, text-based format for storing and exchanging structured data. It is built on two structures: a collection of name/value pairs (objects) and an ordered list of values (arrays). JSON is language-independent but uses conventions familiar to programmers of the C-family of languages, which makes it the de-facto standard for web APIs, configuration files, and NoSQL databases.
Common use cases
- Beautifying minified JSON returned by an API so it is readable.
- Minifying JSON before sending it over the network or saving it to a file.
- Validating JSON configuration files before deployment.
- Debugging malformed JSON payloads that fail to parse.
- Comparing two JSON documents by normalising their formatting.
Frequently asked questions
Does it validate JSON5? No. This tool only supports standard JSON as defined by RFC 8259. JSON5 extensions such as trailing commas, single-quoted strings, comments, or unquoted keys will be reported as errors.
Is my data uploaded? No. All parsing and formatting happens locally in your browser. Your JSON never leaves your device.
What does the error message mean? When parsing fails, the browser reports the position of the problem. Use the message and surrounding text to locate the offending character and fix it.