ライブ検証とプロフェッショナル編集機能付きの高度なJSONエディター
プロフェッショナルツール
Real-time syntax checking with precise error locations as you type, so you catch mistakes instantly
Color-coded keys, strings, numbers, booleans, and null values for easy visual parsing
One-click beautification with customizable indentation to keep your JSON clean and readable
Full edit history so you can experiment freely and revert any changes with keyboard shortcuts
Find and replace values across your entire JSON document with support for nested structures
Your JSON data stays in your browser — nothing is uploaded or stored on any server
よくある質問
Real-time validation catches syntax errors as you type — missing commas, unmatched brackets, invalid values. A plain text editor won't tell you your JSON is broken until you try to parse it.
Yes, the editor handles files up to 100MB. For very large files, the syntax highlighting and validation continue working but may have a slight delay. Use the minify button to reduce file size if needed.
The editor works with standard JSON (RFC 8259). JSON5 features like trailing commas, comments, and unquoted keys are not supported since most APIs and parsers require strict JSON.
Yes. The editor maintains a full undo/redo history. Use Ctrl+Z (Cmd+Z on Mac) to undo and Ctrl+Shift+Z to redo. The history persists until you close the page.
No. Everything runs locally in your browser. Your JSON data is never sent to any server, stored in any database, or logged in any way. Close the tab and the data is gone.