CSV ↔ JSON Converter

About CSV ↔ JSON Converter

This CSV to JSON converter turns spreadsheet exports into JSON and converts JSON back to CSV. Paste data, upload or drag in a .csv or .json file, or load a sample. Options include comma, semicolon, or tab delimiters, using the first row as headers, minified or indented JSON, and how nested objects are handled in JSON to CSV (flatten, stringify, or skip). Quoted fields with commas, line breaks, and escaped quotes are parsed following RFC 4180. Output updates live and can be copied or downloaded, and files are read in your browser rather than uploaded to a server.

How to use

1. Choose CSV to JSON or JSON to CSV; switching modes clears the current input, while the swap button next to them flips the direction and moves the output into the input.
2. Paste your data into the input box, drag and drop a file onto it, click Upload File, or press Load Sample to try it.
3. Set the Delimiter, then Use first row as header and JSON Formatting for CSV input, or Nested Objects handling for JSON input.
4. Leave Live auto convert on to see results instantly, or turn it off and press Convert.
5. Use Copy or Download to export the output, or CLEAR to reset everything.

Limitations & notes

• CSV to JSON outputs every value as a string; numbers and true/false are not converted, and spaces around each value are trimmed.
• In JSON to CSV, Flatten turns arrays into numbered columns such as tags.0 and tags.1, and empty arrays or objects are written as [] or {}; choose Stringify to keep each array or nested object as JSON text in one cell.
• Switching between CSV to JSON and JSON to CSV clears both the input and the result; use the swap button instead to keep converting the current output.
• With Use Header on, rows with missing cells get empty strings, extra cells beyond the header are dropped, and duplicate header names overwrite each other.

FAQ

How do I convert CSV to JSON?

Choose CSV to JSON, paste your data or drop a .csv file, and keep Use first row as header on. Each following row becomes a JSON object keyed by the header names; with the header option off, you get an array of arrays.

How are nested JSON objects converted to CSV?

Flatten turns nested objects into dot-notation columns such as address.city, and arrays into numbered columns such as tags.0 and tags.1. Stringify writes the nested value as a JSON string in a single cell, and Skip leaves those fields out.

Can values contain commas or line breaks?

Yes. Fields wrapped in double quotes can contain the delimiter, line breaks, and doubled quotes (""), as in the RFC 4180 CSV format. When exporting to CSV, values containing these characters are quoted automatically.

Does it support semicolon or tab-separated files?

Yes. Pick Comma, Semicolon, or Tab as the delimiter. Semicolons are common in European Excel exports and tabs are used in TSV files.

Are numbers kept as numbers in the JSON output?

No. Every CSV cell becomes a JSON string, such as "1" rather than 1, because CSV has no type information. Convert types in your own code if you need numbers or booleans.