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JSON Formatter

Uses JavaScript's built-in JSON.parse() to validate and JSON.stringify(obj, null, 2) to indent with two spaces. Everything runs locally in your browser. Related: text case, unix timestamp, color converter.

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Paste JSON to see the formatting process.

What Your Result Means

How This Tool Works

This tool uses JavaScript's built-in JSON.parse() to validate your input against the JSON specification (RFC 8259). If valid, JSON.stringify() reformats it with two-space indentation for readability. All processing happens locally in your browser using no server calls, so confidential data stays on your device. Copy the prettified output for use in code, config files, or API requests.

Quick Questions

What is JSON?

JSON (JavaScript Object Notation) is a lightweight text format for structured data. It uses objects (key-value pairs with curly braces), arrays (square brackets), strings (double quotes), numbers, booleans, and null.

Why does my JSON fail to parse?

Common errors: missing or mismatched quotes, trailing commas, single quotes instead of double quotes, unescaped newlines in strings, or NaN/Infinity values. The error message pinpoints where the parser stopped.

Is my data secure when I paste it here?

Yes. All formatting runs entirely in your browser using JavaScript's built-in functions. No data is sent to servers, logged, or stored. Close the tab and it's gone.

Sources

Method & review

MethodologyHow we calculate this Reviewed & Updated2026-04 Next review2027-04

Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.