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CSV to JSON Converter

Paste or import CSV and convert to structured JSON arrays in your browser.

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CSV TO JSON

Convert CSV and choose field types

Work locally in your browser. String mode preserves leading zeros.

Column type conversion

✓ Converted 2 records

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About the CSV to JSON Converter

Convert CSV and spreadsheet cells to JSON, choosing a type for each column.

Formula or method

Use the first row as headings and validate optional string, number, boolean or auto conversions.

Worked example

Name,Age with Ava,32 can produce {"Name":"Ava","Age":32}.

How to use the tool

  1. Paste CSV with a header row or import a CSV/TSV text file.
  2. Review column names, delimiters and conversion types; preserve identifiers with leading zeros as strings.
  3. Generate the JSON, check representative rows, and download the output.

When this tool is useful

Convert spreadsheet-style CSV rows to structured JSON records in your browser.

What to check before relying on the result

Automatic type conversion can change identifiers or large numbers. Keep such fields as strings and verify quoted CSV cells.

Assumptions and limitations

String is the default; large numbers, dates and identifiers need careful type selection.

Frequently asked questions

Are leading zeros preserved?

Yes, by default every CSV field stays a string.

How can I keep a product code such as 00123 unchanged?

Set its column type to String. Converting it to a number would remove leading zeros.

Continue with a related workflow

Privacy and support

Your inputs are processed locally in your browser. ToolMosaic does not upload or store the values you enter in this tool. Our tools are free, and we appreciate your support.