What Is This Tool?
A JSON formatter takes raw, minified or messy JSON text and rewrites it with consistent indentation and line breaks so it becomes easy to read. JSON (JavaScript Object Notation) is the most common data format used by APIs, configuration files and log systems, but servers usually send it as one long unreadable line to save bandwidth.
This tool also works as a JSON validator: it parses your input using the same strict rules browsers use, so if your JSON has a missing comma, an unquoted key or a trailing comma, you will see the exact error message instead of a silent failure.
Why Use It?
- Debug API responses quickly — turn a one-line response into a readable structure in one click.
- Find syntax errors instantly, with the exact reason the JSON failed to parse.
- Minify JSON before embedding it in code or sending it over the network.
- 100% private: parsing happens in your browser, nothing is uploaded or stored.
- No login, no limits, works on mobile.
How to Use
- Paste your JSON into the input box on the left (or click "Load Example" to try it).
- Choose 2-space or 4-space indentation.
- Click "Format" to beautify, or "Minify" to compress it to a single line.
- If the JSON is invalid, read the error message below the boxes to find the problem.
- Click "Copy" to copy the result to your clipboard.
Example
Input
{"name":"CodeKitHub","tools":["json","base64"],"free":true}Output
{
"name": "CodeKitHub",
"tools": [
"json",
"base64"
],
"free": true
}The same data, formatted with 2-space indentation. Minify does the reverse: it removes all whitespace.
Frequently Asked Questions
Is my JSON data uploaded to a server?
No. This tool runs entirely in your browser using JavaScript. Your JSON never leaves your device, which makes it safe to use with sensitive or internal data.
Why is my JSON invalid?
The most common causes are: missing or extra commas, keys without double quotes, single quotes instead of double quotes, trailing commas after the last item, and comments (JSON does not allow comments). The error message under the input box tells you what the parser found.
What is the difference between Format and Minify?
Format adds indentation and line breaks to make JSON human-readable. Minify removes all unnecessary whitespace to make the JSON as small as possible — useful before transmitting or embedding it.
Is there a size limit?
There is no hard limit imposed by the tool. Very large files (tens of megabytes) may be slow depending on your device, because all processing happens locally in your browser.
Can this fix broken JSON automatically?
No — the tool tells you exactly where the JSON is broken so you can fix it, but it does not guess or change your data. This is intentional: silently "fixing" data can hide real bugs.