Private developer tools

JSON Formatter and Validator

Paste or import JSON to validate it, make it readable, explore its structure, or minify it for production—all without sending data to a server.

Private developer workspace

Paste your JSON

150 B
Indentation

Parsed locally. Your JSON is never uploaded or stored.

Validation result

Valid JSON

Valid
Keys9
Values12
Deepest nesting2
Minified size150 B
{
  "id": 42,
  "name": "Ada Lovelace",
  "active": true,
  "roles": [
    "admin",
    "editor"
  ],
  "profile": {
    "city": "London",
    "joined": "2024-03-18",
    "posts": 128
  },
  "lastSeen": null
}
209 B formatted · 150 B minified

How to use it

Readable JSON in seconds

  1. Paste JSON or import a .json file.
  2. Choose indentation and optional key sorting.
  3. Review formatted, tree, or minified output.
  4. Copy the result or download a JSON file.

Useful validation

Find syntax problems faster

When parsing fails, the formatter reports the nearest line and column and places a caret under the likely problem. Check nearby commas, quotes, brackets, and property names.

How to use it

Get a reliable result

  1. Paste JSON or load the sample document.
  2. Choose indentation and optional key sorting, then format or minify the value.
  3. Review validation feedback and copy or download the result.

Useful for

Common workflows

  • Inspect an API response before debugging it
  • Normalize configuration data for code review
  • Minify a valid JSON document for transport

Examples

What to expect

Nested response
Input
{"user":{"name":"Ada"},"active":true}
Output
An indented object with colored keys, strings, and booleans

Know before you start

Important limitations

  • The parser accepts JSON, not JavaScript object literals, comments, NaN, Infinity, or trailing commas.
  • Sorting is recursive for object keys and can make an order-sensitive visual comparison harder even though JSON object order is not semantic.
  • Very large documents are bounded to protect the browser tab from excessive rendering and memory use.

Keep exploring

More text and developer tools

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Common questions

JSON Formatter FAQ

Is my JSON uploaded?

No. Parsing, formatting, validation, tree inspection, and downloads all happen locally in your browser.

Does formatting change my data?

No. Formatting only changes whitespace. Optional key sorting changes object key order but not keys or values.

Can this tool find JSON errors?

Yes. Invalid JSON displays the parser message and the closest available line and column with a caret.

What indentation styles are supported?

Choose two spaces, four spaces, or tabs. You can also switch to a minified single-line result.

Browser-local

Processed on your device

JSON input and generated results stay in this browser and are never uploaded.

How this processing works

The tool reads and processes this input in your browser. Tool Packer's application server does not receive the input or generated result.

Read the full privacy explanation