JSON Formatter
Beautify, validate, sort, and minify JSON quickly for cleaner development workflows.
Beautify, validate, sort, and minify JSON quickly for cleaner development workflows.
JSON (JavaScript Object Notation) is a lightweight, text-based data format used to store and exchange structured data. It represents data as key-value pairs and ordered lists, making it easy for both humans to read and machines to parse.
Despite its name, JSON is language-independent — nearly every modern programming language (JavaScript, Python, Java, C#, Go, and more) can read and write it natively or through a standard library. This has made JSON the de facto format for REST APIs, configuration files, NoSQL databases, and data interchange between services.
A JSON Formatter is a tool that takes raw, unstructured, or minified JSON text and rearranges it into a clean, indented, human-readable layout — a process often called "beautifying" or "pretty-printing." It also validates the JSON along the way, flagging syntax errors such as missing commas, unquoted keys, or trailing commas.
This JSON Formatter goes further than basic beautification: it lets you format with custom indentation, sort object keys alphabetically, minify JSON down to a single line, validate JSON on demand, and upload or download .json files directly — all running locally in your browser via a Monaco editor.
Paste JSON into the input editor, type it directly, or upload a .json file using the upload panel below the editor.
Pick an indentation size (2, 4, or 8 spaces) and optionally enable "Sort object keys" from the Actions panel on the right.
Click "Format JSON" to beautify it, "Minify JSON" to compact it to one line, or "Validate JSON" to just check it for errors without changing the layout.
The output editor shows the formatted JSON along with a Valid/Invalid badge and an error message if the JSON couldn't be parsed.
Use "Copy Output" to copy the result to your clipboard, or "Download JSON" to save it as a file.
A comma after the last item in an object or array (e.g. {"a": 1, "b": 2,}) is invalid in standard JSON and will cause a parse error.
JSON requires object keys to be wrapped in double quotes. { name: "Alex" } and { 'name': "Alex" } are both invalid — it must be { "name": "Alex" }.
String values must use double quotes, not single quotes. 'Alex' is invalid JSON; it must be "Alex".
JSON has no concept of undefined or NaN. Use null instead, or omit the key entirely.
Standard JSON does not support // or /* */ comments. Remove them, or use a JSON5/JSONC-aware tool if comments are required.
Every { must have a matching }, and every [ must have a matching ]. A single missing or extra bracket will invalidate the entire document.
Numbers like 007 or .5 are not valid JSON numbers. Use 7 and 0.5 instead.
A compact, minified JSON string beautified with 2-space indentation.
Input
{"name":"Alex","age":30,"skills":["JS","SQL"],"active":true}Output
{
"name": "Alex",
"age": 30,
"skills": [
"JS",
"SQL"
],
"active": true
}The same object minified back down to a single line for smaller payloads.
Input
{
"name": "Alex",
"age": 30,
"active": true
}Output
{"name":"Alex","age":30,"active":true}Object keys reordered alphabetically for a consistent, diff-friendly structure.
Input
{
"zip": "10001",
"city": "New York",
"active": true
}Output
{
"active": true,
"city": "New York",
"zip": "10001"
}No. This tool runs entirely client-side in your browser. Your JSON never leaves your device or gets sent to a server.
Formatting (beautifying) adds indentation and line breaks to make JSON easy to read. Minifying strips all unnecessary whitespace to produce the smallest possible payload, which is useful for production API responses or reducing file size.
Most validation failures come from small syntax issues: trailing commas, unquoted keys, single-quoted strings, or mismatched brackets. Check the error message shown in the output panel — it points to the specific issue.
Yes. When "Sort object keys" is enabled, keys are sorted alphabetically at every level of nesting, not just the top level.
No, standard JSON does not support comments. If your source contains // or /* */ comments, remove them before formatting, or use a JSON5/JSONC-specific tool instead.
You can upload .json or .txt files. The contents are loaded directly into the input editor for formatting, minifying, or validation.
Since everything runs in your browser, the practical limit depends on your device's available memory rather than a fixed cap. Very large files (tens of megabytes) may slow down the editor.