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JSON Formatter error
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// about this tool

JSON Formatter Online

Updated 2026-08-19

changelog: 2026-07: examples verified against real output

Format and beautify messy or minified JSON instantly, right in your browser. Paste raw JSON into the editor and SnapTools returns clean, properly indented, human-readable output as you type — with configurable spacing, optional key sorting, and one-click copy or download. Nothing is uploaded: all formatting happens locally, so it's safe for API keys, tokens, and private data.

A well-formatted JSON document is far easier to scan, debug, and review than a single minified line. Whether you're inspecting an API response, tidying a configuration file, or preparing a payload for documentation, the JSON Formatter gives you readable structure in one step.

// how to use

  1. 1 Paste or type your JSON into the input panel on the left — formatting starts as you type.
  2. 2 Open Settings to choose indentation (2, 4, or 8 spaces), sort keys, or compact arrays.
  3. 3 Read the clean, indented result on the right, then click Copy or Download.

// examples

Minified to readable
Input
{"name":"Ada","roles":["admin","dev"],"active":true}
Output
{
    "name": "Ada",
    "roles": [
        "admin",
        "dev"
    ],
    "active": true
}
Nested objects
Input
{"user":{"id":1,"prefs":{"theme":"dark","beta":false}}}
Output
{
    "user": {
        "id": 1,
        "prefs": {
            "theme": "dark",
            "beta": false
        }
    }
}

// reference

Common mistakes the formatter flags (and auto-repairs)

Mistake Why it fails Fix
'single quotes' JSON strings must use double quotes auto-repaired
{ name: 1 } object keys must be quoted auto-repaired
[1, 2, 3,] trailing comma before a closing bracket auto-repaired
// a comment JSON has no comments stripped on repair

// common uses

Debugging API responses Cleaning up exported config files Making log payloads readable Preparing JSON for code review or documentation

// faq

Is my JSON uploaded to a server?
No. Formatting runs entirely in your browser, so your data never leaves your machine — safe for secrets, tokens, and private payloads.
What is the largest file I can format?
The formatter handles inputs up to about 5 MB instantly. Larger files still work but may take a moment to render.
Why does it say my JSON is invalid?
The status bar shows the first syntax error — usually a missing comma, quote, or bracket. Fix that spot and the output updates as you type. For line-by-line errors, try the JSON Validator.
Can it sort object keys alphabetically?
Yes. Open Settings and enable "Sort keys A→Z" to get deterministic, diff-friendly output.
What is the difference between formatting and minifying JSON?
Formatting adds indentation and line breaks to make JSON readable; minifying removes all whitespace to make it as small as possible. Use the JSON Minifier for the latter.

// works with your data

JSON Minifier JSON Sort Keys JSON Validator JSON Viewer JSON to CSV JSON to YAML

Use this via API

Get a free API key → 
curl -X POST https://thesnaptools.com/api/v1/tools/json-formatter \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"json":"{\"name\":\"Ada\",\"roles\":[\"admin\",\"dev\"],\"active\":true}"}'