MARZ.tools

JSON Formatter & Validator

Format, validate, minify, and compare JSON — all in your browser.

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About this tool

Paste JSON to pretty-print it with configurable indentation, validate its syntax with precise error locations, minify it, or compare two JSON documents side by side.

How to use

  1. Paste or type your JSON into the input panel.
  2. Choose format, minify, or compare mode.
  3. Copy the formatted output or view inline validation errors.

FAQ

Is my JSON sent to a server?

No — all parsing and formatting happens locally in your browser using native JSON.parse/stringify. Nothing is uploaded.

What happens if my JSON is invalid?

The tool shows the exact line and character where parsing failed so you can fix it quickly.

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