JSON Formatter
Format, validate, and minify JSON data instantly — with syntax highlighting and error detection.
How to Format and Validate JSON Online
1. Paste your JSON
Paste any JSON data — minified, unformatted, or broken — into the editor. The formatter accepts JSON objects, arrays, strings, and nested structures of any size.
2. Format or validate
Click Format to beautify your JSON with proper indentation and syntax highlighting. Any errors are flagged with the exact line and character position so you can fix them instantly.
3. Copy or minify
Copy the formatted JSON to use in your code, or minify it to strip whitespace for production use. All processing is done in your browser — your data never leaves your device.
What This JSON Formatter Can Do
Format & Beautify
Converts minified or unformatted JSON into properly indented, human-readable output with syntax highlighting.
Validate JSON
Detects syntax errors in your JSON and shows the exact line and position of the problem, just like a JSON validator.
Minify JSON
Strips all whitespace from formatted JSON to produce compact output for APIs, config files, and production deployments.
Format JSON Objects
Works on any valid JSON — objects, arrays, nested structures, and JSON strings with escaped characters.
Error Detection
Highlights invalid JSON with descriptive error messages so you can debug malformed API responses quickly.
No Installation Needed
Use this as an alternative to VS Code JSON formatter or Notepad++ JSON plugins — no extension or install required.
JSON Syntax Quick Reference
| Type | Example | Notes |
|---|---|---|
| Object | {"key": "value"} | Keys must be double-quoted strings |
| Array | ["a", "b", "c"] | Ordered list of values |
| String | "hello world" | Must use double quotes, not single |
| Number | 42 or 3.14 | No quotes — integers or decimals |
| Boolean | true or false | Lowercase only |
| Null | null | Lowercase only |
Frequently Asked Questions
Common questions about JSON Formatter