localcsv.tools
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CONVERT

CSV to JSON Converter

Convert rows into a JSON array of objects, with the first CSV row used as field names. Works locally in your browser, without sending your data to a server.

File processing runs in a separate editor frame. The advertising scripts on this page cannot read or modify the editor contents.

How to use this tool

  1. Paste CSV data or choose a local file.
  2. Keep First row contains headers checked for conventional CSV exports.
  3. Select the correct delimiter if the automatic choice is wrong.
  4. Click Process and download or copy a nicely formatted JSON array.
Privacy note: Your input is processed in your browser, not uploaded to our servers. The original file is never overwritten.

Examples

Example input

name,city Alex,Seoul Robin,Tokyo

Expected result

[{"name":"Alex","city":"Seoul"},{"name":"Robin","city":"Tokyo"}]

What the tool changes (and what it does not)

JSON is easier to process than CSV for many web applications and APIs because each row becomes an object with named properties. For example, a table with name and city columns becomes [{"name":"Alex","city":"Seoul"}]. This utility supports escaped double quotes, line breaks in quoted fields, and commas within a quoted string.

All imported values remain strings. A value such as 00123 stays "00123", which protects product codes, phone-like identifiers, and other fields that should not be coerced into numbers. A downstream application can explicitly convert selected fields to numbers when that is appropriate.

If a header is empty, a safe column_N label is used. Repeated header labels receive unique names to prevent columns from overwriting one another in JSON objects. Files are processed entirely on your device using browser JavaScript.

Frequently asked questions

Does CSV to JSON automatically guess numbers and dates?

No. Every cell remains a string so identifiers and leading zeros are preserved. Convert types later in your own application.

Can JSON keys be derived from the first row?

Yes. The header option is enabled by default. Disable it to generate column_1, column_2, and so on.

Can the tool handle commas inside a cell?

Yes, provided the CSV uses proper quoting, such as "Seoul, Korea" in a single field.