JSON Formatter

Interactive Studio

Format, validate, repair, and minify JSON with custom indentation. Generate TypeScript interfaces and Zod schemas, inspect tree hierarchy, and sort keys — all in your browser. Instant feedback with zero server storage.

Presets:

JSON Raw Input

477 chars

Indentation Spacing

Sort Object Keys (A-Z)

{
  "id": "usr_94819a3b",
  "name": "Elena Rostova",
  "email": "elena.rostova@example.com",
  "isActive": true,
  "age": 28,
  "roles": [
    "admin",
    "developer",
    "maintainer"
  ],
  "settings": {
    "theme": "dark",
    "notifications": {
      "email": true,
      "push": false,
      "frequency": "daily"
    },
    "twoFactorEnabled": true
  },
  "metadata": {
    "lastLogin": "2026-09-26T10:14:22Z",
    "loginCount": 142,
    "ipAddress": "192.168.1.1"
  }
}

Raw Size

477 B

Minified Size

355 B

Minify Savings

26%

Structure

8 Root Keys

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About JSON Formatter

JSON (JavaScript Object Notation) is the universal format for structured data across web APIs and configs. This studio parses your JSON natively, offering instant validation, customizable indentation (2 spaces, 4 spaces, tabs, or single-line minification), recursive alphabetical key sorting, and auto-repair for common trailing comma and quote errors.

Beyond basic formatting, this studio allows you to inspect deep data trees interactively and generate production-ready TypeScript interfaces or Zod schemas with a single click.

How to use JSON Formatter

Paste your JSON into the input.
Errors appear immediately with the position of the problem.
Pick indentation: 2 spaces, 4 spaces, tabs, or minified single-line output.
Optionally sort keys alphabetically, then copy or download the result.

Worked examples

Input: {"b":1,"a":{"c":[1,2]}}

Result: Formatted over several lines with 2-space indent. With sort keys on, "a" comes before "b".

Input: {"a":1,}

Result: Invalid JSON because of the trailing comma. Auto-repair removes it.

Background

JSON allows objects, arrays, strings, numbers, true, false and null. Unlike JavaScript objects, keys must be in double quotes, strings use double quotes, and trailing commas and comments are not allowed. Most parse errors come from these differences.

Minified JSON removes all optional whitespace to reduce payload size. Formatting only changes whitespace, so parsing the formatted and minified versions gives identical data. Parsing runs in your browser, so private payloads are not uploaded.

Common mistakes

Using single quotes or unquoted keys copied from JavaScript code.
Leaving a trailing comma after the last item.
Expecting key order to be preserved after sorting. Sorting reorders keys on purpose.