JSON to CSV Converter

JSON and CSV are two data formats with completely different purposes:

• JSON(JavaScript Object Notation) is a structured data format that supports nested objects and arrays and is suitable for data exchange and API communication between programs.
• CSV(Comma-Separated Values) is a plain text table format. Each row represents a record and each column represents a field. It is a common format for import and export of Excel, Google Sheets, and databases.

The following situations are suitable for converting JSON to CSV:

• API data needs to be imported into Excel or Google Sheets for analysis
• Prepare data sets for machine learning or statistical analysis
• Share structured data with non-technical people (CSV can be opened directly in Excel)
• Import data into the database (MySQL and PostgreSQL support CSV import)
• Generate reports or spreadsheets for review by decision makers

CSV is a two-dimensional table format (rows × columns) and cannot directly represent nested structures. Use this tool Dot Notation Flattening Technology to automatically convert nested objects into flat fields:

{
  "user": {
    "name": "Gary",
    "age": 30
  }
}

user.name,user.age
Gary,30

Flattening rules:

• object → Recursive flattening, Key is concatenated with points, for example profile.address.city
• Array → Save as JSON string in a single cell to avoid field explosion
• Null → Processed according to null value setting (empty string / null / N/A / 0)

When flattening occurs, an orange tip will appear at the top of the tool: "Nested JSON has been automatically flattened."

There are several ways to import CSV into Excel:

1. Open directly: After downloading the .csv file, open it directly with Excel (select UTF-8 encoding)
2. Import from data: Excel → Data → Import from text/CSV → Select file → Specify delimiter and encoding
3. Drag to Google Sheets: Simply drag the .csv file into Google Sheets to automatically parse it

What is UTF-8 BOM?

BOM (Byte Order Mark) is located at the beginning of the file  mark. For CSV files:

• Enable BOM → Excel will automatically recognize UTF-8 encoding and correctly display Chinese, Japanese and other Unicode characters
• No BOM → Excel may be opened with the system default encoding (such as Big5), resulting in garbled characters

💡 If the Chinese characters are garbled after importing the CSV into Excel, please enable the "UTF-8 BOM" option and download again.

The "C" in CSV stands for Comma, but in fact CSV can use different delimiters:

• comma(,) — The most common standard, default for Excel and Google Sheets. However, if the data contains commas (such as the address "Taipei City, Taiwan"), it must be wrapped in quotation marks.
• Semicolon (;) — The default delimiter in Excel in some European regions (since the comma is used as a decimal point). If your CSV doesn't break into columns correctly in Excel, try semicolons.
• Tab（\t） — Also known as TSV (Tab-Separated Values). If commas and semicolons appear frequently in your data, Tab is the safest choice. Many database import tools prioritize TSV.

💡 Not sure which one to use? Use commas first. If Excel does not display properly, try using semicolons instead.

Here are some of the most common problems and solutions:

• Nest object data missing? This tool automatically flattens nested JSON (e.g. profile.age), but if the JSON structure is too complex (such as more than 5 levels of deep nesting), it is recommended to simplify the data before converting.
• Array data is truncated? Array fields are kept in a single cell as a JSON string (e.g. "["a","b","c"]"), it may not be automatically expanded after importing into Excel. You can process further in Excel using "Data → From Table/Range".
• Chinese characters become garbled characters? Enable the "UTF-8 BOM" option and re-download, Excel will correctly recognize UTF-8 encoding.
• CSV all crammed into one column in Excel? Use "semicolon (;)" or "Tab (\t)" as the delimiter instead, or manually specify the delimiter when importing into Excel.

100% safe. This tool adopts a pure front-end (Client-side) architecture, and all JSON parsing and CSV conversion are completed in your browser.No data will be uploaded to any server。

This means:

• Your customer data, API responses, and trade secrets never leave your computer
• No internet connection is required to perform the conversion (except when loading the page for the first time)
• No backend servers store or process your content
• Even ToolHub administrators cannot access the data you enter

Whether you're analyzing customer lists, processing financial data, or transforming confidential API responses, it's safe to do it here.