CSV ↔ JSON オンラインコンバーター

What Is CSV to JSON Converter?

CSV to JSON Converter is a free online tool that transforms CSV data into a JSON array of objects, or converts a JSON array back into CSV format. It reads the first row of your CSV as column headers and maps each subsequent row into a key-value object — making it ideal for data migration, API preparation, and spreadsheet processing workflows.

How to Use CSV to JSON Converter

1. Select the conversion direction: CSV → JSON or JSON → CSV.
2. Paste your CSV or JSON data into the input panel, or click Load Sample to try an example.
3. The converted output appears instantly in the right panel.
4. Click Copy to copy the result, or Swap to reverse the conversion.

Features

• Bidirectional conversion: CSV → JSON and JSON → CSV
• Handles quoted fields and commas inside values
• Swap button to instantly reverse the conversion
• Copy result to clipboard
• Runs entirely in your browser — zero data uploaded

FAQ

What does CSV to JSON Converter do?

It converts a CSV file (with a header row) into a JSON array of objects, where each row becomes an object with keys from the header.

Can I convert JSON back to CSV?

Yes. Switch to JSON → CSV mode and paste a JSON array of objects. The tool generates a CSV with headers derived from the object keys.

Is my data sent to a server?

No. All conversion happens entirely in your browser. Your data never leaves your device.