JSON Formatter & Validator
Beautify, minify, and validate JSON. Paste your data, format it, and copy — all in your browser, nothing uploaded.
データ収集なし
データベースもアカウントもありません。ファイルを見ることはできません。
超高速
ブラウザネイティブ処理 — アップロードなし、待ち時間なし。
100%無料
制限なし、透かしなし、隠れた費用なし。
アカウント不要
サインイン？不要です。ツールを開くだけで使えます。
Formatting and validating JSON
Beautify vs. minify
Beautifying adds indentation and line breaks so JSON is easy to read and debug. Minifying strips all that whitespace to make the smallest possible payload for production or APIs. This tool does both, plus validation.
Instant validation
If the JSON has a syntax error — a trailing comma, a missing quote, an unclosed bracket — the formatter shows the parser's error message so you can find and fix it quickly.
Private by design
Parsing happens entirely in your browser, so sensitive config, tokens, or API responses never leave your device — unlike formatters that send your JSON to a server.
Frequently asked questions
Does it validate as well as format?
Yes. Invalid JSON won't format — instead you get the exact parser error message.
What indentation can I use?
2 or 4 spaces for formatting, or minify to remove whitespace entirely.
Is my JSON uploaded?
No. It's parsed and formatted locally in your browser.
Is there a size limit?
Only your device's memory — there's no server upload limit.