CSV ↔ JSON Converter

Convert CSV to JSON and JSON to CSV. Supports custom delimiters, headers, and nested JSON flattening.

Free Always No Account Needed 100% Client-Side

Delimiter:

CSV Input

JSON Output

[
  {
    "name": "Alice",
    "age": "",
    "email": 30
  },
  {
    "name": "Bob",
    "age": "",
    "email": 25
  },
  {
    "name": "Charlie",
    "age": "",
    "email": 35
  }
]

Preview (first 5 rows)

name	age	email
Alice		30
Bob		25
Charlie		35

How to use CSV ↔ JSON Converter Online

1
Input Data or ParametersPaste your input string, code payload, or select parameters into the editor.
2
Instant Local ComputationThe tool processes your request in real-time inside your browser using client-side JavaScript.
3
Copy or Export OutputCopy the formatted result to your clipboard or download the output payload instantly.

About this tool

CSV (Comma-Separated Values) and JSON are the two most common data formats for tabular data. Converting between them is a frequent task in data processing, ETL pipelines, and spreadsheet integration.

CSV → JSON — converts CSV data to an array of objects, using the first row as keys. Supports comma, semicolon, tab, and pipe delimiters. Handles quoted fields with embedded commas and newlines.

JSON → CSV — flattens an array of JSON objects to CSV. Nested objects are dot-notation flattened (e.g., user.name becomes a column "user.name"). Handles arrays within objects by serializing them as JSON strings.

Paste your data or upload a file, and download the converted result. Preview the first 10 rows in a formatted table before downloading.

Frequently Asked Questions

What delimiters does the CSV parser support?

Comma (,), semicolon (;), tab (\t), and pipe (|). Auto-detection is enabled by default.

How are quoted fields handled?

Fields enclosed in double quotes can contain the delimiter character. Double-double-quotes ("") inside a quoted field represent a literal quote.

What happens with nested JSON in JSON→CSV conversion?

Nested objects are flattened using dot notation. Arrays are serialized as JSON strings in a single cell.

Is there a file size limit?

No server-side limit. Very large files (>50MB) may be slow since processing happens in your browser.

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