JSON ↔ CSV Converter
Convert JSON arrays to CSV and back. Live table preview. Auto-detect types. Custom delimiter.
About This Tool
The DevKit4You JSON ↔ CSV Converter helps you quickly transform structured data between JSON and CSV formats directly in your browser. It supports bidirectional conversion, live table previews, automatic type detection, custom delimiters, and nested object flattening.
This tool is designed for developers, analysts, data engineers, QA teams, and anyone working with APIs, spreadsheets, databases, or structured datasets. Everything runs locally in your browser with no uploads or external processing.
How to Use — JSON → CSV
Switch to the JSON → CSV tab and paste a JSON array of objects. Each object becomes a row; the keys of the first object become column headers.
[
{ "name": "Alice", "age": 30, "active": true },
{ "name": "Bob", "age": 25, "active": false }
]
Select the delimiter for the CSV output: , (comma, default), ; (semicolon for European locales), Tab, or Pipe |.
Press CONVERT to generate the CSV. A live table preview appears below. Use Copy or Download to save the result.
name,age,active
Alice,30,true
Bob,25,false
How to Use — CSV → JSON
Switch to the CSV → JSON tab and paste CSV content. Make sure "First row is header" is checked if your CSV has column headers.
name,age,active
Alice,30,true
Bob,25,false
Keep "Infer types" checked to automatically convert "42" → 42, "true" → true, and "null" → null for clean JSON output.
Click CONVERT to generate structured JSON. Numbers and booleans are typed correctly, and the table preview lets you verify the output before copying.
[
{ "name": "Alice", "age": 30, "active": true },
{ "name": "Bob", "age": 25, "active": false }
]
Key Capabilities
Convert JSON arrays to CSV and CSV back to JSON arrays. Both directions produce a live table preview so you can verify the structure before copying or downloading.
Choose comma, semicolon, tab, or pipe as the field separator. Semicolon is required for European locales (where comma is the decimal separator); tab produces TSV files compatible with Excel.
During CSV → JSON conversion, string values are automatically cast to their correct types: numeric strings become numbers, true/false become booleans, and empty strings become null.
Nested JSON structures are automatically flattened using dot notation. {"user":{"name":"Alice"}} produces a column called user.name — compatible with most spreadsheet and database import workflows.
JSON vs CSV — Quick Reference
| Feature | JSON | CSV |
|---|---|---|
| Structure | Hierarchical, nested | Flat, tabular rows |
| Data types | String, number, boolean, null, array, object | All values are strings by default |
| Best for | APIs, config files, web apps | Spreadsheets, databases, ETL |
| Human readable | Yes, but verbose | Yes, very compact |
| Tool support | JavaScript, REST APIs, NoSQL | Excel, Google Sheets, SQL COPY |
| Nested data | Native support | Requires flattening |
Privacy & Transparency
All conversions happen entirely in your browser using JavaScript. No JSON or CSV data is transmitted to any server at any point — not even for logging or analytics.
We do not store JSON data, save CSV files, log converted content, or track what you paste. Nothing is retained after you close the page.
The tool works fully offline once the page is loaded. No third-party data processing services are contacted during conversion.
🔒 Safe & Secure
All conversion runs locally in your browser. Your data — including sensitive API responses, personal records, or proprietary datasets — never leaves your device.
✅ Completely Free
Our tool is free to use with no limits on data size, conversion count, or format. No account or signup required — open the page and start converting immediately.