How are CSV headers determined?

The first row of the CSV is treated as the header row and used as JSON object keys. Each subsequent row becomes an object with those keys.

Which delimiters are supported?

Comma (default), semicolon, and tab. Select the delimiter that matches your CSV data. Auto-detection is not performed; choose explicitly.

Fields wrapped in double quotes can contain the delimiter, newlines, and escaped quotes ("""). The parser follows RFC 4180 conventions.

An array of objects, each with keys from the header row. Values are always strings; numeric coercion is left to the consumer.

Yes. The tool accepts a JSON array of objects and uses the union of keys as the header row. Missing values are emitted as empty fields.

No. All parsing and serialization happen locally in your browser. The tool is safe for sensitive datasets.

Convert between CSV and JSON online. Supports comma, semicolon, and tab delimiters。無料、プライベート、100%クライアントサイド。

モードparam.delimiter

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出力

Local only

How are CSV headers determined?: The first row of the CSV is treated as the header row and used as JSON object keys. Each subsequent row becomes an object with those keys.
どの区切り文字に対応していますか？: Comma (default), semicolon, and tab. Select the delimiter that matches your CSV data. Auto-detection is not performed; choose explicitly.
How are quoted fields with commas handled?: Fields wrapped in double quotes can contain the delimiter, newlines, and escaped quotes ("""). The parser follows RFC 4180 conventions.
What JSON shape is produced from CSV?: An array of objects, each with keys from the header row. Values are always strings; numeric coercion is left to the consumer.
Can I convert JSON to CSV?: Yes. The tool accepts a JSON array of objects and uses the union of keys as the header row. Missing values are emitted as empty fields.
データはどこかにアップロードされますか？: No. All parsing and serialization happen locally in your browser. The tool is safe for sensitive datasets.