Your files stay in this browser and are not uploaded to OmniTools.

CSV ↔ JSON Converter

Convert CSV and JSON locally and download the result.

Open workspace directly

About this tool

CSV and JSON Converter changes tabular CSV data into JSON records and converts compatible JSON arrays back to CSV. All parsing is performed locally. It is intended for ordinary tables with a header row; nested objects, mixed arrays and spreadsheet formulas need manual review because a flat CSV cannot represent every JSON structure.

When it is useful

  • Prepare CSV records for a small development task.
  • Open a JSON array in spreadsheet software.
  • Inspect a data export before importing it elsewhere.

How to use it

  1. Choose the correct conversion direction.
  2. Paste or upload data that contains no unnecessary secrets.
  3. Check headers, delimiters, quotes and a few sample rows.
  4. Download the output and validate it in the destination system.

Quality and privacy notes

Dates, long identifiers and leading zeros may be interpreted differently by spreadsheet applications after download. Keep an original copy and verify row counts before using converted data in a production import.

Important limits

  • Nested JSON is flattened only where supported.
  • The tool does not validate a business schema.
  • Large datasets can exceed browser memory.

Frequently asked questions

Why did a leading zero disappear in Excel?

Spreadsheet software may interpret the value as a number. Import that column explicitly as text.

Is the uploaded data sent to OmniTools?

No. The current converter processes it in the browser.