JSON Formatter & Validator

Beautify messy JSON, minify it, or validate it — with the exact line and column of any error.

JSON Formatter & Validator

🔒 Nothing you enter is sent anywhere or stored. All processing happens in your browser.

How it works

JSON (JavaScript Object Notation) is the most common format for exchanging structured data between programs. It's readable in principle, but real-world JSON often arrives minified onto one line or with inconsistent spacing. This tool cleans it up and checks it for errors.

Format parses your JSON and re-prints it with consistent indentation (2 spaces, 4 spaces, or tabs) so nested objects and arrays become easy to scan. Minify does the opposite, stripping all unnecessary whitespace to produce the smallest valid string for transmission or storage. Validate simply confirms whether the input is well-formed JSON.

When JSON is invalid, the tool reports the browser's parse error and calculates the line and column where parsing failed, so you can jump straight to the missing comma, unquoted key, or stray bracket. Because parsing uses the browser's native JSON engine and runs entirely on your device, you can safely paste API responses or config files containing sensitive values.

Examples

Minified {"a":1,"b":[2,3]} → Format → neatly indented multi-line JSON.
Missing comma → error like "Unexpected string (line 3, column 5)".
Pretty config → Minify → single compact line ready to embed.

Frequently asked questions

What does 'validate' actually check?
It attempts to parse your input with the browser's JSON engine. If it parses, the JSON is syntactically valid; if not, you get the error and its location.
Why does it show a line and column for errors?
The native parser reports a character position; the tool converts that into a line and column so you can find the problem quickly in your text.
Does formatting change my data?
No. It only changes whitespace and indentation. Keys, values, and structure stay identical — Minify and Format are lossless round-trips.
Is my JSON uploaded anywhere?
No. Parsing happens locally in your browser, so API keys or personal data in your JSON never leave your device.