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Paste CSV to get structured JSON, or paste JSON to produce a flat CSV. You can customize the delimiter, header row handling, and indentation. All processing runs in your browser using PapaParse, with no server uploads.
Conversion: Delimiter: JSON Fmt:
CSV Input
Upload File
Ln 1, Col 1 CSV
JSON Output
JSON

How to Use CSV ↔ JSON Converter

  1. 1. Paste Your CSV or JSON

    Paste CSV data or JSON into the input panel, or load a sample to get started.

  2. 2. Choose Direction and Delimiter

    Select CSV → JSON or JSON → CSV, and set the delimiter (comma, semicolon, tab, etc.).

  3. 3. Copy or Download the Output

    The converted result appears right away; copy it to your clipboard or download as a file.

The Technical Details

This interactive web utility provides fast, reliable, and completely private data transformations. In modern workflows, quick formatting, conversions, or estimations are essential. By running all logic entirely in your browser with client-side JavaScript, this tool guarantees that your data never leaves your machine. This approach delivers maximum performance and absolute data privacy, as no information is ever sent to a server.

Frequently Asked Questions

Is nested JSON supported?

Flat JSON objects convert cleanly. Deeply nested structures are flattened when converting to CSV, since CSV is a flat format.

Can I use custom delimiters?

Yes. The tool supports comma, semicolon, tab, pipe, and custom delimiter characters.

Is any data sent to a server?

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

How are large files handled?

The tool processes data in-memory in your browser. Very large files (tens of MB) may be slow, but no size limit is enforced.