JSON & CSV Converter

A powerful online tool for converting between JSON and CSV formats. Format, validate, and beautify your data with syntax highlighting. All processing happens locally in your browser for maximum privacy and security.

JSON Input
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CSV Output
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Fast & Efficient

Instant conversion with real-time validation and formatting. Supports large files and complex data structures.

Secure & Private

All processing happens locally in your browser. Your data never leaves your device.

Developer Friendly

Syntax highlighting, error detection, and formatting tools to help you work efficiently.

Common Use Cases

Data Analysis

  • Convert JSON data to CSV for spreadsheet analysis
  • Format and validate data structures
  • Export data for reporting and visualization

Data Integration

  • Convert CSV data to JSON for API integration
  • Format and validate data structures
  • Integrate different data formats

Frequently Asked Questions

Is this tool free to use?

Yes, this tool is completely free to use with no limitations or registration required.

How is my data protected?

All conversion and formatting is done locally in your browser. Your data never leaves your device or is sent to any server.

What file sizes are supported?

The tool can handle reasonably large files, but extremely large files may be limited by your device's memory.

Can I convert complex data structures?

Yes, the tool supports nested objects, arrays, and all standard JSON and CSV data types.

Example

Input JSON:

[
  {
    "name": "John Doe",
    "age": 30,
    "email": "[email protected]",
    "active": true,
    "tags": ["developer", "javascript"],
    "address": {
      "city": "New York",
      "country": "USA"
    }
  },
  {
    "name": "Jane Smith",
    "age": 25,
    "email": "[email protected]",
    "active": false,
    "tags": ["designer", "ui/ux"],
    "address": {
      "city": "London",
      "country": "UK"
    }
  }
]

Output CSV:

name,age,email,active,tags,address
"John Doe",30,[email protected],true,"developer,javascript","New York,USA"
"Jane Smith",25,[email protected],false,"designer,ui/ux","London,UK"

Implementation in Different Languages

JavaScript:


function jsonToCsv(jsonData) {
  if (!Array.isArray(jsonData) || jsonData.length === 0) {
    throw new Error("Input must be a non-empty array of objects");
  }

  // Get headers from first object
  const headers = Object.keys(jsonData[0]);
  
  // Create CSV header row
  const headerRow = headers.join(",");
  
  // Create data rows
  const dataRows = jsonData.map(obj => {
    return headers.map(header => {
      const value = obj[header];
      if (value === null || value === undefined) return "";
      if (typeof value === "string") {
        return value.includes(",") || value.includes('"') 
          ? `"${value.replace(/"/g, '""')}"` 
          : value;
      }
      return String(value);
    }).join(",");
  });

  return [headerRow, ...dataRows].join("\n");
}

Python:


import csv
import json

def json_to_csv(json_data):
    if not isinstance(json_data, list) or not json_data:
        raise ValueError("Input must be a non-empty array of objects")
    
    # Get headers from first object
    headers = json_data[0].keys()
    
    # Write to CSV
    output = []
    output.append(",".join(headers))
    
    for obj in json_data:
        row = []
        for header in headers:
            value = obj.get(header, "")
            if isinstance(value, str):
                if "," in value or '"' in value:
                    value = f'"{value.replace("""", """""")}"'
            row.append(str(value))
        output.append(",".join(row))
    
    return "\n".join(output)