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JSON Formatter & Validator

Instantly format, validate, minify and explore JSON data. Syntax highlighting, interactive tree view, error detection with precise line numbers — all in your browser.

✓ Format & Beautify ✓ Validate & Fix Errors ✓ Minify / Compact ✓ Tree View Explorer ✓ Syntax Highlighting
10M+JSONs Formatted
InstantReal-time Validation
RFC 8259JSON Standard
0Sign-up Required
Indent:
⚠️
JSON Syntax Error
Input JSON
Output
Formatted
Tree View
Minified
Formatted JSON will appear here…
Ready

How to Use the JSON Formatter

1

Paste or Upload JSON

Paste your raw, minified, or malformed JSON directly into the input panel. Or click "Upload" to load a .json file from your device. Try the sample buttons to explore the formatter.

2

Format, Validate or Minify

Click "Format / Beautify" to indent and prettify your JSON with syntax highlighting. "Validate" checks your JSON against the RFC 8259 standard. "Minify" strips all whitespace for production use.

3

Copy, Download or Explore

Copy the output to clipboard, download as a .json file, or switch to Tree View to interactively browse and collapse nested objects and arrays. All data stays in your browser.

Why Use ToollLive JSON Formatter?

🎨

Syntax Highlighting

Keys, strings, numbers, booleans and null values are colour-coded for instant visual clarity.

🌲

Interactive Tree View

Explore complex nested JSON visually. Collapse and expand objects and arrays with one click.

⚠️

Precise Error Detection

Invalid JSON is flagged immediately with the exact error message from the JavaScript engine parser.

📐

Flexible Indentation

Choose 2-space, 4-space, or tab indentation for your formatted output to match your code style guide.

Real-time Validation

The status bar updates live as you type, showing valid/invalid state, key count, size, and nesting depth.

🔒

100% Private

All JSON processing uses JavaScript's native JSON.parse() in your browser. No data is ever sent to a server.

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Free Online JSON Formatter, Validator & Beautifier

ToollLive's free JSON formatter is the fastest way to format, validate, and beautify JSON online. Paste any raw, minified, or malformed JSON and instantly get a perfectly indented, syntax-highlighted output — with precise error messages if your JSON is invalid. Our tool uses JavaScript's native JSON.parse() engine, which means validation follows the RFC 8259 JSON standard exactly — not a custom ruleset.

Switch to Tree View to browse nested objects and arrays interactively, collapsing branches you don't need. Use Minify to strip all whitespace and produce compact JSON ready for production APIs. Choose your preferred indentation (2 spaces, 4 spaces, or tabs). The real-time status bar shows key count, file size, and nesting depth. Everything runs entirely in your browser — your JSON data is never transmitted to any server, making it completely safe for sensitive API responses and configuration files.

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