JSON Formatter, Validator & Viewer — Free & Private
Use this free JSON formatter to beautify messy data, validate syntax with line-level error inspection, and explore nested structures in an interactive JSON viewer — all in your browser. No uploads, no signup — your data never leaves your device.
Your data never leaves your browser
Input
Editor
FormatValidateTree viewAuto-repair
Output
Formatted output appears here when your JSON is valid.
Stats
Stats appear when JSON is valid.
Ready — paste JSON to begin🔒 Client-side only
Ctrl/Cmd+V to paste · Ctrl/Cmd+Enter to format
About this tool
JSON formatterJSON validatorJSON viewerFix & FormatTree navigationCopy path
How to use
- Paste or upload your JSON into the input panel on the left.
- The validator checks syntax instantly — invalid lines are highlighted in red with line:column details.
- Click Format to beautify, or Fix & Format to repair common syntax errors automatically.
- Switch to the Tree tab to explore nested data as a JSON viewer — click nodes to jump in the editor, copy dot paths, and search.
- Use Copy or Download to export the formatted result.
Examples
Messy JSON → formatted
{"name":"ToolsCandy","tags":["json","free"],}{
"name": "ToolsCandy",
"tags": [
"json",
"free"
]
}Broken JSON → repaired
{ name: 'demo', active: true, }{
"name": "demo",
"active": true
}