Toolkeel

CSV to JSON converter

Move data between spreadsheets and code: turn a CSV export into a JSON array, or a JSON API response into a CSV you can open in Excel.

  • Free
  • Private
  • No sign-up
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How to use it

  1. Paste data or open a file.

  2. Choose CSV → JSON or JSON → CSV.

  3. Copy or download the result.

About this tool

The CSV parser follows RFC 4180: fields with commas, quotes or line breaks inside double quotes are handled correctly, and doubled quotes ("") become one. Semicolon-separated files, which Excel produces in many European and Middle Eastern locales, are detected automatically. Numbers with leading zeros (such as phone numbers or postcodes like 007) stay as text so they are not damaged.

When converting JSON to CSV, every key found in any object becomes a column; nested objects are written as JSON text in their cell.

Good to know

  • Files up to 30 MB.
  • JSON to CSV needs an array of objects or arrays.
  • Excel may need "Data › From Text/CSV" to read UTF-8 correctly.

Frequently asked questions

How do I convert an Excel sheet to JSON?

In Excel, save as "CSV UTF-8", open the file here and choose CSV → JSON.

Why are some numbers kept as text?

Values with leading zeros or more than 15 digits are kept as text so phone numbers, codes and IDs are not changed.

Can it handle commas inside values?

Yes, as long as those values are wrapped in double quotes, as standard CSV requires.

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Last updated 2026-10-20 by the Toolkeel team. How we build and check our tools.