“You want to use Excel data in an app” or “you need to analyze API data in a spreadsheet” - both require converting between CSV and JSON.

In this article, we explain how to convert between CSV and JSON, covering header rows, delimiters and Japanese data, with concrete examples.

What are CSV and JSON?

CSV (Comma-Separated Values)

CSV represents tabular data as text. It is widely used for Excel and Google Sheets exports and database dumps.

name,age
Taro,30
Hanako,25

JSON (JavaScript Object Notation)

JSON is the standard format for web APIs and configuration files. It can express nested structures and is easy to handle in programs.

[
  { "name": "Taro", "age": "30" },
  { "name": "Hanako", "age": "25" }
]

Which should I use? CSV suits spreadsheet software; JSON suits programs and APIs. Converting between them is handy depending on the task.

Key points when converting

Keep these three points in mind:

Point Detail
Header row If the first CSV row is column names, they become the JSON keys
Delimiter Commas are common, but tabs and semicolons are also used
Quotes Fields containing commas or line breaks are wrapped in quotes (“) in CSV

With a header row

Using the first row as column names produces an array of JSON objects:

name,age
Taro,30
[
  { "name": "Taro", "age": "30" }
]

Without a header row

The first row is treated as data:

Taro,30
[
  { "column1": "Taro", "column2": "30" }
]

How to convert CSV to JSON

The Tools Hub CSV to JSON converter handles this in your browser in seconds.

1

Paste your CSV

Copy CSV from Excel or a spreadsheet and paste it into the input field.

2

Set the delimiter and header row

Choose comma, tab or semicolon, and toggle whether the first row is a header.

3

Convert and copy

Press convert to see the formatted JSON, then copy or download it.

Tool mentioned in this article

CSV to JSON Converter

Supports comma, tab and semicolon delimiters. Runs entirely in your browser - data is never sent externally.

Convert now

How to convert JSON to CSV

Switch the direction to “JSON → CSV” and follow the same steps.

  • The JSON must be an array of objects
  • If all objects share the same keys (columns), you get a clean CSV
  • Fields containing commas or line breaks are automatically wrapped in quotes

Notes on Japanese data

Japanese CSV and JSON convert as-is when handled in UTF-8. A few tips:

  • CSV created in Excel may use Shift_JIS (CP932). Save it as UTF-8 first to be safe
  • When opening a UTF-8 CSV in Excel, it may display garbled characters. Saving with a UTF-8 BOM helps

Note: Fields containing commas must be wrapped in quotes (") in CSV. Converters handle this automatically, but be careful when editing manually.

Summary

  • CSV suits spreadsheets; JSON suits programs
  • Header rows and delimiters are the key settings when converting
  • Commas and line breaks inside data are escaped with quotes
  • The Tools Hub converter works entirely in your browser with no external data transfer

When you need to convert between CSV and JSON for data migration or development, follow the steps in this article.

FAQ

Can I change the CSV delimiter?

Yes. Choose between comma, tab and semicolon. Tab-delimited data (TSV) works too.

What happens without a header row?

Turn off “header row” and the tool assigns keys like “column1” and “column2” automatically.

Can it handle large datasets?

It depends on browser memory, but tens of thousands of rows are handled without issues.

Is my data sent to a server?

No. All processing happens in your browser, and your data is never sent externally.