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JSON驗證器

免費線上JSON驗證器。在瀏覽器中即時處理資料。無上傳,無註冊,完全私密。

Local processing

What is JSON驗證器?

A JSON validator checks whether a string is well-formed JSON according to RFC 8259. Valid JSON uses double-quoted strings, supports objects, arrays, numbers, booleans, and null, and disallows trailing commas and comments. The validator parses the input and reports either success or a precise error — including the line, column, and a human-readable reason — so the user can fix the problem at its source.

How It Works

The tool attempts JSON.parse on the input string. If parsing succeeds, the input is valid and the tool reports the parsed structure's type and size. If parsing throws a SyntaxError, the error message is parsed to extract the character offset, which is converted to a line and column number for display. A lenient mode may optionally accept JSON5 (single quotes, trailing commas, comments) but strict mode follows the RFC.

Common Use Cases

  • Checking API request bodies — confirm a payload is valid before sending it to a server
  • Validating config files — catch syntax errors in JSON configuration before deployment
  • Debugging parse failures — locate the exact position of a missing comma or unquoted key
  • Linting data exports — verify that a generated JSON file is structurally correct

Technical Details

Standard: RFC 8259 (strict JSON). Disallowed: trailing commas, single-quoted strings, comments, unquoted keys, NaN/Infinity. Error reporting: character offset converted to 1-based line and column. The validator does not check schema conformance (use JSON Schema for that). Maximum input size is bounded by browser string/memory limits.

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驗證器免費嗎?

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。

What JSON standards are supported?

The validator follows RFC 8259 (the official JSON specification). It rejects trailing commas, single-quoted strings, comments, unquoted keys, and NaN/Infinity values. For lenient parsing (JSON5 features), use the JSON Formatter tool which may accept extended syntax.

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