Is my JSON sent to a server?

No. All formatting and validation happen locally in your browser. Your data never leaves your device.

What does the validator check?

It parses your input as JSON and reports the first syntax error with its line and column so you can fix it quickly.

What's the difference between format and minify?

Format (pretty-print) adds indentation for readability; minify removes all whitespace to produce the smallest valid JSON.

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JSON Formatter & Validator

Pretty-print, minify, and validate JSON with error reporting.

Input JSON

Indent

Processing happens locally in your browser — never paste secrets or production data into any online tool unless you trust it. This tool does not send your input anywhere.

About the JSON formatter

JSON (JavaScript Object Notation) is the most common data format for APIs and config files. This tool pretty-prints messy JSON, minifies it for transport, and validates it with precise error locations.

Paste your JSON, choose an indentation level, and click Format or Minify. Valid output can be copied or downloaded.

Frequently asked questions

Is my JSON sent to a server?: No. All formatting and validation happen locally in your browser. Your data never leaves your device.
What does the validator check?: It parses your input as JSON and reports the first syntax error with its line and column so you can fix it quickly.
What's the difference between format and minify?: Format (pretty-print) adds indentation for readability; minify removes all whitespace to produce the smallest valid JSON.