Free · Reliable output · No signup

Convert CSV to JSON

Turn a CSV into an indented JSON array of objects, with stable keys for blank or duplicate headers.

Add as many files as you need. Up to 1 GiB per file. Keep this tab open until your downloads finish.

Batch conversion uses the standard settings. Open Customize a file below to change them.

Conversion starts as soon as you choose files. Files download automatically when ready. Your browser may ask to allow multiple downloads.

Customize a file · settings, paste and edit

CSV → JSON

Free conversion in your browser. Your file stays on this device.

Local processing

8 fictional sales rows · CC0

Choose your CSV
Open a file, paste CSV text, or try the sample.
Review the preview
Adjust available settings and check the output. Edit CSV lets you change source values.
Copy or download
Save your .json file with the current settings.

Output preview

Example output

[
  {
    "Project": "Website",
    "Status": "Ready"
  },
  {
    "Project": "Docs",
    "Status": "In progress"
  }
]

Preview is limited to the first 20 rows and 16,000 characters. Download includes every row within the tool limits.

Three simple steps

How to convert CSV to JSON

1. Open your CSV
Choose several CSV files and convert them together. For column settings, pasted text or editing, open Customize a file. The first row supplies column headers.
2. Review the output
Follow each file’s progress. View opens a short preview without leaving the page; use Customize a file when you need different format settings.
3. Save your result
Copy the complete output or download a .json file. Downloads start when files are ready, with a Download button for every result. No signup or payment is required.

Output contract

What the JSON converter writes

Each CSV row becomes one JSON object. Column labels become object keys; blank and duplicate source headers receive stable, unique names so no value is overwritten.

The preview is bounded so larger files stay manageable. Downloads use the complete parsed document within the format limits, including changes made in the editor.

Parsing and conversion happen on your device. Your CSV is not uploaded to a conversion server. An error preserves the current input so you can adjust settings or edit the source and try again.

Plain answers

JSON conversion questions

Is this a real JSON file?+

Yes. The download is valid JSON text created from the parsed CSV table.

When is the download created?+

The output preview appears after parsing. Copy and download generate the complete output with your current settings; the preview can show fewer rows than the exported file.

What happens to data types?+

Cells stay as text by default, preserving identifiers and leading zeroes. SQL and SQLite allow explicit column types; invalid values are reported before download.