新着

JSONフォーマッター

JSONデータの整形、検証、圧縮ができます。エラーメッセージと統計情報、カスタマイズ可能なインデントで即座に構文検証が可能です。

すべての処理はブラウザ内で行われます — データがサーバーに送信されることはありません。標準JSON形式（RFC 8259）をサポートしています。

How to Use This Tool

  1. 1

    Paste your JSON

    Paste or type raw JSON into the text area. You can also click 'Sample' to load example data.

  2. 2

    Validate and format

    The tool instantly validates your JSON. Click 'Format' to pretty-print it with your chosen indentation (2, 4, or 8 spaces).

  3. 3

    Minify if needed

    Click 'Minify' to compress the JSON by removing all whitespace — useful for reducing payload sizes in API requests.

  4. 4

    Review stats and copy

    View total keys, nesting depth, and file size. Click 'Copy' to copy the formatted or minified JSON to your clipboard.

Frequently Asked Questions

What is JSON and why does formatting matter?
JSON (JavaScript Object Notation) is a lightweight data-interchange format. Formatting (pretty-printing) adds indentation and line breaks, making it human-readable for debugging and code review.
How does JSON validation work?
The tool uses the browser's built-in JSON.parse() function. If parsing succeeds, the JSON is valid. If it fails, the specific syntax error message is displayed to help you find the issue.
What is the maximum JSON size supported?
The tool accepts up to 500,000 characters of input, which is sufficient for most API responses and configuration files.
Can this tool fix broken JSON?
No. This is a formatter and validator, not a repair tool. It will report the exact error location to help you fix issues manually — such as missing commas, unclosed brackets, or invalid escape sequences.