~/tools/json-to-csv-converter

JSON ↔ CSV Converter

Convert JSON → CSV and CSV → JSON instantly. Flattens nested objects, supports custom delimiters, and exports with one click. Runs entirely in your browser — nothing is sent to a server.

// How to use

1. Pick direction: JSON→CSV or CSV→JSON
2. Paste data or upload a file
3. Choose delimiter & flatten options
4. Output updates in real time
5. Copy or Download the result
* all processing happens in browser

// delimiter
// flatten nested(address.city · arrays→json string)
input.json
[
  {
    "id": 1,
    "name": "Alice",
    "email": "alice@example.com",
    "age": 28,
    "address": {
      "city": "Seoul",
      "country": "KR"
    }
  },
  {
    "id": 2,
    "name": "Bob",
    "email": "bob@example.com",
    "age": 34,
    "address": {
      "city": "Busan",
      "country": "KR"
    }
  },
  {
    "id": 3,
    "name": "Carol",
    "email": "carol@example.com",
    "age": 25,
    "address": {
      "city": "Incheon",
      "country": "KR"
    }
  }
]
output.csv

JSON to CSV Converter — What It Does

This tool converts between JSON (JavaScript Object Notation) and CSV (Comma-Separated Values) formats directly in your browser. Both directions are supported: paste a JSON array to get a CSV spreadsheet, or paste CSV rows to get a structured JSON array.

Unlike most online converters, this tool handles nested JSON objects by flattening them using dot notation (e.g., address.city). It also supports custom delimiters, proper CSV quoting per RFC 4180, and automatic type inference when converting CSV to JSON.

Features

Bidirectional

Convert JSON → CSV or CSV → JSON with a single click toggle.

Nested JSON Flatten

Deep objects are flattened to dot-notation headers like address.city, user.role.name.

Custom Delimiters

Choose between comma, semicolon, tab, or pipe as the field separator.

File Upload

Drag & drop or click to upload .json or .csv files of any size.

One-click Download

Download the converted result as a .csv or .json file instantly.

Type Inference

CSV → JSON automatically converts numbers, booleans, and nulls to proper types.

RFC 4180 Quoting

Fields containing delimiters, quotes, or newlines are correctly quoted and escaped.

No Server

All conversion happens in your browser. Your data never leaves your machine.

Common Use Cases

API → Spreadsheet

Export REST API responses directly to CSV for analysis in Excel or Google Sheets.

Database Export

Convert JSON-formatted database exports (MongoDB, DynamoDB) to CSV for BI tools.

Data Migration

Transform CSV imports from legacy systems into JSON for modern APIs and NoSQL databases.

Log Analysis

Convert JSON log arrays to CSV for filtering and aggregation in spreadsheet tools.

Config Export

Export JSON configuration objects to CSV for bulk editing and re-import.

Data Science Prep

Prepare JSON datasets into tabular CSV format for pandas, R, or other analysis tools.