jtcsv - JSON <-> CSV toolkit for Node.js and browser


Fast JSON <-> CSV conversion with streaming helpers, NDJSON/TSV support, and optional integrations.

Features

- JSON <-> CSV conversion with security defaults
- Streaming helpers and async iterator API
- NDJSON and TSV helpers
- Browser bundle with Web Worker helpers
- Optional plugin system and framework adapters
- CLI and optional TUI
- Performance‑optimized – fast number parsing, single‑pass BOM stripping, efficient delimiter detection

Installation

``bash
npm install jtcsv
`

$3

`bash
npm install @jtcsv/tui
npm install @jtcsv/excel exceljs
npm install @jtcsv/validator
`

Quick start (Node.js)

`javascript
const { jsonToCsv, csvToJson } = require('jtcsv');

const data = [
{ id: 1, name: 'John', email: 'john@example.com' },
{ id: 2, name: 'Jane', email: 'jane@example.com' }
];

const csv = jsonToCsv(data, { delimiter: ',', includeHeaders: true });
const json = csvToJson(csv, { delimiter: ',', parseNumbers: true });

console.log(csv);
console.log(json);
`

$3


`javascript
const { csvToJsonIterator } = require('jtcsv');

const csv = 'id,name\n1,Jane\n2,John';

$3

JTCSV includes a powerful CLI for batch conversion, file processing, and data transformation.

`bash


Convert CSV file to JSON

npx jtcsv csv-to-json data.csv --output data.json

Convert JSON to CSV with custom delimiter

npx jtcsv json-to-csv data.json --delimiter ";" --output out.csv

Stream processing with NDJSON

npx jtcsv csv-to-ndjson large.csv --stream > output.ndjson

See all options

npx jtcsv --help
`

Full documentation: CLI.md
for await (const row of csvToJsonIterator(csv, { fastPathMode: 'compact' })) {
console.log(row);
}
`

Browser usage


- Bundler: import { csvToJson, jsonToCsv } from 'jtcsv/browser';
- CDN UMD: https://cdn.jsdelivr.net/npm/jtcsv/dist/jtcsv.umd.js
- CDN ESM: https://cdn.jsdelivr.net/npm/jtcsv/dist/jtcsv.esm.js

See README-browser.md for full browser API and worker helpers.

CLI


`bash
npx jtcsv csv-to-json input.csv output.json
npx jtcsv json-to-csv input.json output.csv
npx jtcsv stream csv-to-json big.csv output.json
npx jtcsv batch json-to-csv "data/*.json" output/

optional TUI

npx jtcsv tui
`

See CLI.md for full command list and options.

Demos


Run these from the repo root:
`bash

Express API demo

npm run demo

Web demo (Vite dev server on http://localhost:3000)

npm run demo:web

Preview built demo

npm run demo:serve
`

From inside demo/ use:
`bash
npm run dev
npm run preview
npm run serve
`

Plugin system


The plugin-enabled API is exported from jtcsv/plugins.

`javascript
const { create } = require('jtcsv/plugins');

const jtcsv = create();
jtcsv.use('my-plugin', { name: 'My Plugin', version: '1.0.0' });
`

See README-PLUGINS.md and plugins/README.md for integrations.

Development


Run from the repo root:
`bash
npm test
npm run test:coverage
npm run test:coverage:entry
npm run test:coverage:ts
npm run test:types
npm run tsc:types
npm run build
`

Linux validation (Docker):
`bash
docker run --rm -v /path/to/jtcsv:/work -w /work node:20 bash -lc "npm ci && npm test"
`

License


MIT. See LICENSE`.