Convert CSV to JSON and JSON to CSV

Spreadsheets export as CSV, but APIs and modern apps speak JSON. This tool converts either direction, correctly handling quoted fields that contain commas, line breaks, or embedded quotes — the details that break naive "just split on commas" approaches.

Features:

• RFC 4180 quoting: Fields with commas, quotes, or newlines are parsed correctly.
• Custom delimiters: Comma, semicolon, or tab.
• Header row toggle: Convert with or without treating the first row as column names.
• Client-side only: Your data never leaves your browser.

1. Why CSV Quoting Trips People Up

A naive CSV parser that just splits every line on commas breaks the moment a field contains a comma of its own, like "Doe, Jane" as a name. The CSV standard handles this by wrapping such fields in double quotes, and escaping a literal quote inside as "". This tool follows those rules in both directions.

2. From CSV to JSON

With a header row, each CSV row becomes a JSON object keyed by the column names. Without a header, you get an array of arrays — useful when the CSV represents a matrix or has no meaningful column names.

3. From JSON to CSV

An array of objects converts to CSV using the union of every object's keys as the header row, in the order they first appear. Nested objects or arrays inside a field are converted to their JSON string form, since CSV has no native way to represent nested data.