Browser-local JSON formatter

JSON Formatter Online

Turn compact JSON into a readable structure with consistent indentation. Your input stays on this device.

Indent

Local processing · private

Input JSON6 lines · 143 B

Ctrl/⌘ + Enter to runPaste, type, or drop a .json file

Result

{
  "site": "jsonminify.org",
  "private": true,
  "tools": [
    "minify",
    "format",
    "validate"
  ],
  "settings": {
    "indent": 2,
    "download": true
  }
}

169 B · 0 B saved✓ Valid JSON

Original size143 B

Result size169 B

Reduction—

StatusValid JSON

No account · no upload · no installation

Processed in your browser

Standard JSON validation

No account or upload

01 — 03

Readable JSON in three steps

Formatting starts with strict validation, so the result is both consistent and valid.

Add compact JSON

Paste JSON or choose a local .json file up to 10 MB.

Choose indentation

Select two or four spaces, then format the complete document.

Copy or download

Review the readable result and use it in your editor, documentation, or test fixture.

EXAMPLES & SYNTAX

Input, output, and common errors

The parser preserves JSON values while changing only the representation required by this tool.

INPUT

{
  "site": "jsonminify.org",
  "enabled": true,
  "items": [1, 2]
}

OUTPUT

{
  "site": "jsonminify.org",
  "enabled": true,
  "items": [
    1,
    2
  ]
}

CaseValid formWhy it matters

Object keys{"name":"value"}

Keys and string values require double quotes.

Arrays[1, 2, 3]

Items keep their original order.

Primitive valuestrue · false · null

These tokens are lowercase and are not quoted.

Whitespacespace · tab · line break

Optional outside strings; meaningful inside quoted strings.

Invalid JSON example{ "enabled": true, }

A trailing comma is valid in some JavaScript contexts but not in JSON. Remove it before running parsed operations.

WHY JSONMINIFY.ORG

Formatting without hidden changes

The formatter rewrites whitespace only after standard JSON parsing succeeds.

Consistent indentation

Normalize nested objects and arrays with a predictable two- or four-space layout.

Strict validation first

Trailing commas, comments, and unquoted keys are reported instead of silently repaired.

Local by design

Formatting, copying, and download preparation happen entirely in your browser.

COMMON USE CASES

When readable JSON matters

Formatting helps humans inspect structure, review changes, and explain data without changing the values consumed by software.

Review an API response

Expand a compact response into nested objects and arrays that are easier to scan during debugging or integration work.

Prepare documentation examples

Create consistent code samples for API guides, support articles, tickets, and technical discussions without manually aligning braces and commas.

Audit configuration files

Reveal nesting and sibling keys before reviewing a configuration change, checking an exported setting, or comparing environments.

Make diffs easier to read

Normalize indentation before a code review so structural edits are separated from inconsistent whitespace changes.

JSON REFERENCE

How JSON formatting works

Formatting is a serialization step performed after strict parsing. It improves presentation but does not add schema checks or repair invalid source.

Two spaces versus four spaces

Two spaces keep documents relatively compact and are common in web projects. Four spaces create stronger visual separation for deeply nested data. Both outputs represent the same JSON value.

Objects and arrays keep their hierarchy

Opening and closing braces or brackets move to predictable levels, while commas separate sibling values. The formatter does not flatten nested structures.

Strings and numbers are preserved as JSON

Escaped characters remain valid JSON strings and numeric values remain numbers. Formatting does not convert values into a different type.

Formatting is not schema validation

A document can be valid JSON but still violate an API contract. Use a JSON Schema validator when you need required fields, formats, ranges, or business rules.

FAQ

JSON formatting questions

What the formatter changes, what it rejects, and where your data is processed.

Does the formatter change JSON values?

No. It parses standard JSON and writes the same values with consistent whitespace and indentation.

Can I choose tabs instead of spaces?

This version supports two or four spaces so results stay predictable across editors and platforms.

Will invalid JSON be formatted?

No. The tool reports the error location and preserves your original input for correction.

Is my JSON uploaded?

No. Parsing and formatting run locally in the browser and the site does not receive your JSON.