CSV to JSON

RFC 4180 Compliant Parser

The converter uses a battle-tested RFC 4180 compliant CSV parser that correctly handles quoted fields, embedded commas, escaped quotes, and newlines within fields.

// Example CSV with complex quoting:
name,description,tags
"Smith, John","He said ""Hello""","tag1;tag2"
"Multi
line","Field with newline","tag3"

Parsed correctly into:
[
  { name: "Smith, John", description: "He said "Hello"", tags: "tag1;tag2" },
  { name: "Multi
line", description: "Field with newline", tags: "tag3" }
]

Header Row Handling

When First row is header is enabled (default), the first CSV row becomes object keys. When disabled, columns are named column0, column1, etc.

// CSV:
id,name,email
1,Alice,alice@example.com
2,Bob,bob@example.com

// With header=true (default):
[{"id":"1","name":"Alice","email":"alice@example.com"},...]

// With header=false:
[{"column0":"1","column1":"Alice","column2":"alice@example.com"},...]

Empty Cell Replacement

Empty cells are replaced with a customizable placeholder. By default, empty cells become empty strings.

// CSV with empty cells:
id,name,email
1,Alice,
2,,bob@example.com

// With missing = "N/A":
[{"id":"1","name":"Alice","email":"N/A"},
 {"id":"2","name":"N/A","email":"bob@example.com"}]

// With empty missing (default):
[{"id":"1","name":"Alice","email":""},
 {"id":"2","name":"","email":"bob@example.com"}]

Privacy-First Processing

All CSV parsing and JSON generation happens entirely in your browser. No data is ever sent to a server.

• CSV input never leaves your device
• Generated JSON is created client-side
• File downloads use browser Blob APIs
• Works completely offline after initial load

Array of Objects (Default)

Standard JSON array with pretty-printed formatting (2-space indentation). Best for readability and direct use in JavaScript.

[
  {
    "id": "1",
    "name": "Alice",
    "email": "alice@example.com"
  },
  {
    "id": "2",
    "name": "Bob",
    "email": "bob@example.com"
  }
]

Minified JSON

Compact single-line JSON with no whitespace. Smallest file size, ideal for APIs, storage, and network transfer.

[{"id":"1","name":"Alice","email":"alice@example.com"},{"id":"2","name":"Bob","email":"bob@example.com"}]

JSONLines / NDJSON

Each object on its own line. Perfect for streaming, log processing, big data pipelines, and tools like jq, pandas, or Elasticsearch bulk API.

{"id":"1","name":"Alice","email":"alice@example.com"}
{"id":"2","name":"Bob","email":"bob@example.com"}

Programmatic Usage

The core engine supports all three formats via the format option.

import { parseCsvToJson } from './engine.js';

const csv = `id,name
1,Alice
2,Bob`;

// Array of Objects (pretty)
parseCsvToJson(csv, { format: 'array' });

// Minified
parseCsvToJson(csv, { format: 'minified' });

// JSONLines/NDJSON
parseCsvToJson(csv, { format: 'jsonlines' });