100% client-side, nothing ever leaves your browser
Free JSON Formatter & Validator
Format, validate, beautify, and minify JSON instantly in your browser. Paste your data, catch syntax errors down to the exact line and column, and copy or download the result — nothing is uploaded, ever.
Tip: press Ctrl + Enter to format. Your JSON is processed entirely in your browser — nothing is uploaded or stored.
Formatted or minified JSON will appear here.
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How this JSON formatter works
Paste or upload your JSON
Type it directly, drop a .json file onto the editor, or click Upload File to browse for one.
Your browser validates and formats it locally
Syntax is checked as you type, with the exact line and column of any error, entirely on your device.
Copy or download the result
Grab the formatted or minified output with one click, or save it as a .json file.
Common use cases
A few everyday situations where a fast, private JSON formatter comes in handy.
API responses
Paste a minified API response to instantly see its structure while building or debugging an integration.
Configuration files
Clean up and validate JSON config files before committing them, catching typos before they break a build.
Debugging
Track down a malformed payload quickly using exact line and column error reporting instead of guessing.
Web development
Inspect fixture data, mock responses, or local storage contents in a readable, indented view.
Data exchange
Minify JSON before sending it over the network to shave off unnecessary bytes, or format it when handing data off to a teammate.
Frequently asked questions
What is JSON?
JSON, short for JavaScript Object Notation, is a lightweight text format for structuring data using objects, arrays, strings, numbers, booleans, and null. It's the standard way APIs, configuration files, and countless applications exchange and store structured data.
How do I format JSON?
Paste or upload your JSON into the input panel and click Format JSON, or press Ctrl+Enter. The tool re-indents the structure with consistent spacing so nested objects and arrays are easy to read, and highlights keys, strings, numbers, and booleans.
Is this JSON formatter free?
Yes. It's free to use with no limits, no account, and no watermark on anything you copy or download.
Does this tool upload my data?
No. Your JSON is processed entirely in your browser using JavaScript. Nothing is sent to a server, logged, or stored, whether you paste text directly or upload a file from your device.
What is JSON validation?
Validation checks whether text follows correct JSON syntax, such as matching brackets, properly quoted keys, and valid value types. This tool validates as you type and points to the exact line and column where a problem occurs if the JSON is invalid.
What is the difference between formatted and minified JSON?
Formatted JSON adds indentation and line breaks so humans can read the structure easily. Minified JSON strips all unnecessary whitespace to produce the smallest possible file size, which is preferable for production API responses and configuration files sent over a network.
More tools
Additional utilities from the same toolkit.