TOOL · 01
JSON Formatter & Validator
Paste JSON below to beautify, validate or minify it. All processing happens locally in your browser.
Input
Output
About JSON Formatter
JSON (JavaScript Object Notation) is a lightweight data-interchange format. Use Format to make compressed JSON readable, Validate to check for syntax errors, and Minify to shrink JSON for production use.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format. It is easy for humans to read and write, and easy for machines to parse and generate. Built on two universal structures — objects (key/value pairs) and arrays (ordered lists) — JSON has become the common language of data on the web.
Nearly every programming language can parse and produce JSON, which makes it the default format for web APIs, configuration files, NoSQL databases and messaging systems.
Features
Beautify
Reformat compressed or messy JSON with clean 2-space indentation.
Validate
Catch syntax errors instantly, with the exact position reported.
Minify
Strip all whitespace to shrink payloads for production use.
100% private
Everything runs in your browser — your data never leaves the page.
Full Unicode
Chinese, emoji, any language — encoded and preserved correctly.
Free forever
No registration, no limits, no watermarks. Just paste and go.
How to use
-
1
Paste your JSON
Drop any JSON text into the input box above — minified API responses, config files, log lines, anything.
-
2
Pick an action
Format to beautify it, Validate to check for errors, or Minify to compress it.
-
3
Copy the result
Grab the output with one click and use it wherever you need it.
Use cases
API debugging
Turn minified API responses into readable, indented JSON in one click.
Config files
Validate package.json, tsconfig.json or app settings before deploying.
Log analysis
Pretty-print structured log lines to spot problems quickly.
Data inspection
Examine payloads exchanged between services, queues and databases.
Learning & teaching
Show how JSON structure maps to real-world data, live in class.
Payload shrinking
Minify JSON before embedding it in requests, pages or firmware.
Syntax quick reference
{
"name": "TmpIO",
"tools": 9,
"free": true
}{
name: 'TmpIO',
"tools": 9,
}Common mistakes: trailing commas, single quotes, unquoted keys and comments — none of these are allowed in strict JSON.
FAQ
Is my JSON data uploaded to a server?
No. All processing happens locally in your browser with plain JavaScript. Nothing is transmitted or stored.
What is the difference between Format and Minify?
Format adds indentation and line breaks for readability; Minify removes all unnecessary whitespace to reduce size. Both produce semantically identical JSON.
Why does my JSON fail validation?
The most common causes are trailing commas, single-quoted strings, unquoted keys, comments, or undefined values. The error message points to the exact position of the problem.
Is JSON the same as a JavaScript object?
Not exactly. JSON is a text format inspired by JavaScript object syntax, but it is stricter: keys must be double-quoted, and functions, undefined and comments are not allowed.