JSONデータ
JSONスキーマ（任意）
機能とヒント
- • リアルタイムのJSON構文検証
- • 詳細なエラーメッセージによるスキーマ検証
- • 一般的な用途向けの既製スキーマテンプレート
- • JSONデータから自動的にスキーマを生成
- • JSON Schema draft-07機能のサポート
- • フォーマット検証（email、date、UUIDなど）
- • 検証結果をクリップボードにコピー
- • JSONファイルを直接アップロード
JSON looks simple until a missing comma or an unclosed brace breaks an entire API response or config file, and the error message from most parsers just says something unhelpful like "unexpected token" without telling you where to look. This tool parses your JSON in the browser and points directly to the line and character where the syntax breaks, so you can fix malformed API payloads, config files, or hand-edited data without scanning the whole document character by character. It's built for developers who need a fast sanity check before shipping JSON into a request body, a `.json` config, or a database seed file.
Paste or type your JSON into the editor and validation runs as you work, checking for the usual culprits: trailing commas, unquoted keys, mismatched brackets, and invalid escape sequences. When something is wrong, you get a precise line-number error instead of a vague failure, which is the difference between a five-second fix and five minutes of hunting. Beyond basic syntax checking, the tool also supports JSON Schema validation, so you can check that a document not only parses correctly but actually matches the structure — required fields, types, nested objects — that your application expects.
Because everything runs client-side in your browser, nothing you paste is uploaded anywhere, which matters if you're validating JSON that contains API keys, tokens, or other data pulled from a real system rather than a sanitized test fixture. A common workflow is to validate a raw API response here first when your own code throws a parsing error, since it's often faster to confirm whether the JSON itself is broken before you start debugging your parser.
Check any JSON document for syntax errors and optionally validate it against a JSON Schema.
Paste or type the JSON you want to check into the input editor.
The tool parses the JSON automatically and shows whether it's valid; if not, it reports the exact line and character where the syntax error occurs.
Jump to the flagged line, correct the issue — such as a trailing comma, missing quote, or mismatched bracket — and let the tool re-check it.
If you need to verify structure, not just syntax, supply a JSON Schema and the tool will validate the document's fields and types against it.
Once the document passes validation, copy the clean JSON for use in your API call, config file, or codebase.