JSON 格式化工具
在瀏覽器中即時格式化、美化與驗證 JSON。無需上傳，完全私密。
Local processingWhat is JSON 格式化工具?
A JSON formatter (also called a beautifier or pretty-printer) takes compact or minified JSON and re-emits it with consistent indentation, line breaks, and spacing so a human can read it. JSON (JavaScript Object Notation) is the de facto data interchange format for web APIs. A formatter also surfaces syntax errors — if the input is not valid JSON, the parser reports the location and nature of the problem, making it a validator as well.
How It Works
The tool parses the input string with a JSON parser (JSON.parse or a lenient parser that accepts trailing commas and comments). If parsing succeeds, the resulting value is re-serialized with a configurable indent (typically 2 spaces) and sorted-key option. If parsing fails, the parser's error message is displayed with the character offset so the user can locate the issue. All processing is local; no data is sent to a server.
Common Use Cases
- Reading minified API responses — expand a single-line JSON payload into readable, indented output
- Debugging malformed JSON — locate the exact position of a missing comma or bracket
- Comparing config files — consistent indentation makes diffs and reviews easier
- Preparing JSON for documentation — pretty-printed examples are clearer in READMEs and specs
Technical Details
Parser: native JSON.parse (strict, RFC 8259 compliant). Indentation: 2 spaces by default, configurable. Output is UTF-8. The formatter does not sort keys by default to preserve insertion order. Trailing commas and comments are not valid JSON; if present, parsing fails with a syntax error. Maximum practical input size is bounded by browser memory (typically several MB).
How to Use
Enter your input above. The result updates automatically. Use the copy button to copy the result.
Privacy
All processing happens in your browser. Your data is never uploaded to any server.
FAQ
這個 JSON 格式化工具免費嗎？
是的，完全免費。無需註冊。
這個工具會上傳我的資料嗎？
不會。所有處理都在瀏覽器中本機完成。您的資料永遠不會離開您的裝置。