JSON Formatter
Format, validate, or minify JSON online instantly — paste your data, pick a mode, and see the result update live.
- Input Characters
- 0
- Output Characters
- 0
CleanTextly's JSON Formatter is a free online JSON formatter, validator, and minifier that runs entirely in your browser. Paste a minified API response, a config file, or hand-written JSON, and instantly format, pretty-print, or beautify it with readable indentation, validate its syntax with a clear error message if something's wrong, or minify it down to a compact single line — all in one tool, with nothing ever uploaded to a server.
Features
Format & Pretty-Print
Beautifies JSON with clean, consistent 2-space indentation, turning a minified or hand-typed blob into JSON that's easy to read and review.
Instant Validation
Acts as a JSON syntax checker as you type, showing a clear "Valid JSON" confirmation or a specific error the moment something breaks.
Minify JSON
Strips all formatting whitespace to produce compact JSON for storage or transmission — minifying `{ "name": "John" }` produces `{"name":"John"}` — while text inside strings is always left untouched.
Clear, Located Error Messages
Invalid JSON shows a specific error message — including the line and column where parsing failed when it can be determined — instead of a generic failure or a raw browser exception.
Handles Any Valid JSON
Correctly formats, validates, and minifies deeply nested objects and arrays, Unicode text and emoji, escaped strings, and root-level arrays or primitive values — not just objects.
100% Private
Everything runs locally in your browser using the native JSON parser. Your data is never uploaded, logged, or stored anywhere.
How to Use
- 1
Paste your JSON
Add the JSON you want to format, validate, or minify into the input box.
- 2
Choose a mode
Select Format to pretty-print it, Validate to check its syntax, or Minify to compact it.
- 3
Check the result
A "Valid JSON" confirmation appears instantly, or a clear, specific error message if the syntax is invalid.
- 4
Copy or download
Copy the result with one click, or download it as a .txt file.
Example
Formatting a Minified API Response
Input
{"id":101,"name":"Jordan Lee","active":true,"roles":["admin","editor"]}Output
{
"id": 101,
"name": "Jordan Lee",
"active": true,
"roles": [
"admin",
"editor"
]
}Common Use Cases
Debugging API Responses
Paste a minified or raw API response to instantly see its structure and spot formatting mistakes.
Working with Configuration Files
Format compact config files like package.json or tsconfig.json for easier reading and review, or validate them before committing.
Checking JSON Before Using It
Validate hand-written or generated JSON — catching missing commas, unclosed brackets, or malformed quotes — before using it in your application or code.
Reducing JSON Size for Transmission or Storage
Minify JSON to remove unnecessary whitespace before sending it over a network or storing it, without changing the underlying data.
Frequently Asked Questions
A JSON formatter — also called a JSON beautifier or JSON pretty print tool — takes JSON data and rewrites it with consistent indentation and line breaks, making it easier to read without changing the underlying data.
JSON pretty printing is the process of adding indentation and line breaks to JSON so its structure is easy to read, without changing any of the underlying data. This tool pretty-prints JSON automatically in Format mode, using consistent 2-space indentation.
A JSON beautifier is another name for a JSON formatter — a tool that reformats JSON with readable indentation and spacing. CleanTextly's Format mode works as a JSON beautifier, turning minified or messy JSON into a clean, readable structure.
A JSON validator checks whether a piece of text is syntactically valid JSON, acting as a JSON syntax checker that flags problems like trailing commas, unquoted keys, or unclosed brackets.
Paste your JSON into the input box and select Format — CleanTextly instantly pretty-prints it with 2-space indentation, right in your browser, with no upload required.
Yes. Everything runs directly in your browser using JavaScript's built-in JSON parser — there's nothing to install, and no account or sign-up is needed.
Paste your JSON and select Validate. A "Valid JSON" message appears instantly if the syntax is correct, or a specific error describing what went wrong if it isn't.
JSON minification removes all unnecessary whitespace — spaces, tabs, and line breaks — between JSON tokens to produce the smallest valid JSON, e.g. minifying `{ "name": "John" }` produces `{"name":"John"}`. Whitespace inside string values is never touched.
Formatting adds indentation and line breaks to make JSON easier for a person to read. Minifying does the opposite — it removes that formatting whitespace to make the JSON as compact as possible for storage or transmission. Both represent exactly the same data.
No. Formatting only adds or removes whitespace — indentation, line breaks, and spacing. The actual data (keys, values, types, and structure) is never altered.
You'll see a clear error message instead of any output — including the line and column where parsing failed when it can be determined — so nothing is silently guessed at or partially formatted.
The most common causes are a trailing comma after the last item, an unquoted or single-quoted property name, a missing closing brace or bracket, or a value like `undefined` that isn't valid JSON. The error message shown points to roughly where parsing failed.
No. Formatting, validation, and minification all happen entirely in your browser. Your JSON is never sent to a server or stored.