JSON Toolkit

Fast, private JSON tools that run in your browser.

🔒 Data stays in your browser

CSV to JSON Converter

Turn CSV from Excel, Google Sheets or any export into JSON. The header row becomes the object keys, the delimiter is detected automatically, and numbers, true/false and empty cells become proper JSON values. You can also open a .csv file from your computer; it is read in your browser and never uploaded.

JSON ⇄ CSV Converter

Turn CSV from a spreadsheet or export into JSON. Quoted values, line breaks inside quotes and Excel files are handled, and the delimiter is detected automatically.

How to use the CSV to JSON Converter

  1. Paste your CSV, or click Open file… to load a .csv or .tsv file.
  2. Check the options: whether the first row is a header, and whether to convert numbers and booleans.
  3. Click Convert to JSON, then copy, download, or open the result in the formatter.

Features

  • Automatic delimiter detection: comma, semicolon, tab or pipe
  • Quoted fields with commas, quotes and line breaks (RFC 4180)
  • Handles Excel's byte order mark and Windows line endings
  • Careful type conversion: values like 007 and long IDs stay as text
  • Warnings for rows with missing or extra values, and for blank or duplicate headers
  • Rows become objects, or arrays when there is no header row

Frequently asked questions

Why does 007 stay as text instead of becoming a number?
Converting it would turn 007 into 7 and lose the leading zeros, which matter for zip codes, product codes and IDs. Long numbers that JavaScript cannot store exactly are kept as text for the same reason.
My CSV uses semicolons. Will it work?
Yes. The delimiter is detected from the first line, and you can also choose it yourself.
What about decimals written with a comma, like 24,99?
They are kept as text, because 1,234 could mean either one thousand two hundred thirty-four or one point two three four.

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