入力JSON
0 文字数
1
整形済み出力
1
JSONフォーマッターの使い方
- • 入力パネルにJSONを貼り付けるかファイルをアップロードする
- • エラーのハイライト付きリアルタイム検証
- • フォーマット設定のカスタマイズ（インデント、ソート）
- • 分割・ツリー・RAWビューの切り替え
- • ツリービューで複雑なJSON構造を探索する
- • ツリービューの値をクリックしてパスと値をコピー
- • ツリービューモードでJSON内を検索する
- • 整形済みJSONをダウンロードまたはクリップボードにコピー
Anyone who works with APIs, config files, or log exports eventually hits a wall of unreadable JSON — a single unbroken line of braces and commas that's technically valid but impossible to scan by eye. The JSON Formatter & Beautifier takes that raw text and reflows it into properly indented, human-readable structure, so nested objects and arrays are visually distinguishable at a glance. It's built for the moment you paste a minified API response or a compressed config blob and just need to see what's actually in it.
Paste or type your JSON into the input area and the tool parses it, checks the syntax, and renders a beautified, color-highlighted version with consistent indentation. If the JSON is malformed — a missing comma, an unclosed bracket, a stray trailing comma — the validator flags the problem so you can locate and fix it instead of guessing. When you need the opposite result, the same tool minifies formatted JSON down to a single compact line, stripping whitespace for smaller payloads or embedding in code. It's built to handle large files without choking, so pasting a sizeable export doesn't leave you staring at a frozen tab.
Because formatting and validation happen entirely client-side in your browser, nothing you paste is uploaded anywhere — useful when the JSON contains API keys, internal config, or other data you'd rather not send to a server. There's no signup and no file size gimmicks; open the page, paste your data, and get a readable or validated result immediately. It's a handy habit to run any third-party JSON response through the validator once before wiring it into your code, since a syntax error caught here is far cheaper than one caught at runtime.
Format messy JSON data and validate JSON syntax using our online JSON formatter tool.
Copy your unformatted or minified JSON and paste it into the input editor.
Click the "Format" button to automatically add proper indentation, line breaks, and spacing.
The tool automatically validates JSON syntax and highlights any errors with helpful messages.
Choose your preferred indentation size (2 or 4 spaces) and whether to sort keys alphabetically.
Click the copy button to copy the formatted JSON to your clipboard.