# @json2csv/node > Node.js Transform and Async interface to convert JSON into CSV. Latest version **7.0.8** (published 2026-08-06) · MIT license · 0 weekly downloads ## Install ```sh npm install @json2csv/node pnpm add @json2csv/node yarn add @json2csv/node bun add @json2csv/node ``` ## Health **Score 75/100 (B)** — status: active. Positive: has types; esm support; no vulnerabilities; has provenance; recently updated; high maintenance score; high quality score. Warnings: low downloads. ## Facts | | | |---|---| | Version | 7.0.8 | | Published | 2026-08-06 | | First published | 2022-08-21 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | bundled | | Module format | ESM + CommonJS | | Dependencies | 1 | | Unpacked size | 99.5 KB | | Known vulnerabilities | 0 | | Install scripts | no | | Provenance | attested (GitHub Actions) | | GitHub stars | 365 | | Author | Juanjo Díaz | | Maintainers | juanjodiaz | | Keywords | json, to, csv, export, convert, parse | ## Links - npm: https://www.npmjs.com/package/@json2csv/node - Repository: https://github.com/juanjoDiaz/json2csv - Homepage: https://juanjodiaz.github.io/json2csv - Issues: https://github.com/juanjoDiaz/json2csv/issues - npm.io page: https://npm.io/package/@json2csv/node ## Dependencies (1) - [@json2csv/plainjs](https://npm.io/package/@json2csv/plainjs.md) ^7.0.8 ## Alternatives - [@mapbox/jsonlint-lines-primitives](https://npm.io/package/@mapbox/jsonlint-lines-primitives.md) — 5.3M weekly downloads - [reftools](https://npm.io/package/reftools.md) — 3.5M weekly downloads - [@hey-api/openapi-ts](https://npm.io/package/@hey-api/openapi-ts.md) — 3.5M weekly downloads - [@mapbox/geojson-rewind](https://npm.io/package/@mapbox/geojson-rewind.md) — 2.4M weekly downloads - [turbo-stream](https://npm.io/package/turbo-stream.md) — 1.7M weekly downloads ## Recent versions - 7.0.8 (latest) — 2026-08-06 - 7.0.7 — 2026-07-16 - 7.0.6 — 2024-02-11 - 7.0.5 — 2024-01-20 - 7.0.4 — 2023-11-28 - 7.0.3 — 2023-08-24 - 7.0.2 — 2023-08-17 - 7.0.1 — 2023-05-31 - 7.0.0 — 2023-05-29 - 6.1.3 — 2023-04-03 - 6.1.2 — 2022-11-14 - 6.1.1 — 2022-11-08 - 6.1.0 — 2022-10-30 - 6.0.0 — 2022-09-27 - 6.0.0-alpha.4 — 2022-09-11 - … 1 more at https://npm.io/package/@json2csv/node/versions ## README # @json2csv/node [![npm version](https://badge.fury.io/js/@json2csv%2Fnode.svg)](https://badge.fury.io/js/@json2csv%2Fnode) [![npm monthly downloads](https://img.shields.io/npm/dm/@json2csv/node.svg)](https://badge.fury.io/js/@json2csv%2Fnode) [![Node.js CI](https://github.com/juanjoDiaz/json2csv/actions/workflows/on-push.yaml/badge.svg)](https://github.com/juanjoDiaz/json2csv/actions/workflows/on-push.yaml) [![Coverage Status](https://coveralls.io/repos/github/juanjoDiaz/json2csv/badge.svg?branch=main)](https://coveralls.io/github/juanjoDiaz/json2csv?branch=main) [![license](https://img.shields.io/npm/l/@json2csv/plainjs)](https://raw.githubusercontent.com/juanjoDiaz/json2csv/main/LICENSE.md) Fast and highly configurable JSON to CSV converter. It fully support conversion following the [RFC4180](https://datatracker.ietf.org/doc/html/rfc4180) specification as well as other similar text delimited formats as TSV. `@json2csv/node` exposes two modules to integrate `json2csv` with the Node.js Stream API for stream processing of JSON data. This package includes two modules: * **[Node Transform](#node-transform):** Node.js Transform Stream that ingests JSON and outputs csv. Ideal to process streams (http responses, file contents, ...) in Node.js. * **[Node Async Parser](#node-async-parser):** Wraps the `Node Transform` to offer a friendly promise-based API. ### Features - Fast and lightweight - Support for standard JSON as well as NDJSON - Scalable to infinitely large datasets (using stream processing) - Advanced data selection (automatic field discovery, underscore-like selectors, custom data getters, default values for missing fields, ...) - Support for custom input data transformation - Support for custom csv cell formatting. - Highly customizable (supporting custom quotation marks, delimiters, eol values, etc.) - Automatic escaping (preserving new lines, quotes, etc.) - Optional headers - Unicode encoding support - Pretty printing in table format to stdout ### Other json2csv packages There are multiple flavours of json2csv: * **[Plainjs](https://www.npmjs.com/package/@json2csv/plainjs):** Includes the `Parser` API and a new `StreamParser` API which doesn't the conversion in a streaming fashion in pure js. * **[Node](https://www.npmjs.com/package/@json2csv/node):** Includes the `Node Transform` and `Node Async Parser` APIs for Node users. * **[WHATWG](https://www.npmjs.com/package/@json2csv/whatwg):** Includes the `WHATWG Transform Stream` and `WHATWG Async Parser` APIs for users of WHATWG streams (browser, Node or Deno). * **[CLI](https://www.npmjs.com/package/@json2csv/cli):** Includes the `CLI` interface. And a couple of libraries that enable additional configurations: * **[Transforms](https://www.npmjs.com/package/@json2csv/transforms):** Includes the built-in `transforms` for json2csv (unwind and flatten) allowing the using to transform data before is parsed. * **[Formatters](https://www.npmjs.com/package/@json2csv/formatters):** Includes the built-in `formatters` for json2csv (one for each data type, an excel-specific one, etc.). Formatters convert JSON data types into CSV-compatible strings. ## Requirements - Node v20+ ## Installation ### **NPM** You can install json2csv as a dependency using NPM. ```bash $ npm install --save @json2csv/node ``` ### **Yarn** You can install json2csv as a dependency using Yarn. ```bash $ yarn add --save @json2csv/node ``` ## Node Transform For Node.js users, the Streaming API is wrapped in a Node.js Stream Transform. This approach ensures a consistent memory footprint and avoids blocking JavaScript's event loop. The async API takes a second options arguments that is directly passed to the underlying streams and accepts the same options as the standard [Node.js streams](https://nodejs.org/api/stream.html#stream_new_stream_duplex_options), plus the options supported by the `Stream Parser`. This Transform uses the `StreamParser` under the hood and support similar events. ### Usage ```js import { createReadStream, createWriteStream } from 'fs'; import { Transform } from '@json2csv/node'; const input = createReadStream(inputPath, { encoding: 'utf8' }); const output = createWriteStream(outputPath, { encoding: 'utf8' }); const opts = {}; const transformOpts = {}; const asyncOpts = {}; const parser = new Transform(opts, asyncOpts, transformOpts); const processor = input.pipe(parser).pipe(output); // You can also listen for events on the conversion and see how the header or the lines are coming out. parser .on('header', (header) => console.log(header)) .on('line', (line) => console.log(line)); ``` #### Parameters ##### Options * `ndjson` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) indicates that the data is in NDJSON format. Only effective when using the streaming API and not in object mode. * `fields` [<DataSelector[]>](/docs/advanced-options/data-selection.md) Defaults to toplevel JSON attributes. * `transforms` [<Transform[]>](/docs/advanced-options/transforms.md) Array of transforms to apply to the data. A transform is a function that receives a data recod and returns a transformed record. Transforms are executed in order. * `formatters` [<Formatters>](/docs/advanced-options/formatters.md) Object where the each key is a Javascript data type and its associated value is a formatters for the given type. * `defaultValue` [<Any>]() value to use when missing data. Defaults to `` if not specified. (Overridden by `fields[].default`) * `delimiter` [<String>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) delimiter of columns. Defaults to `,` if not specified. * `eol` [<String>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) overrides the default OS line ending (i.e. `\n` on Unix and `\r\n` on Windows). * `header` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) determines whether or not CSV file will contain a title column. Defaults to `true` if not specified. * `includeEmptyRows` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) includes empty rows. Defaults to `false`. * `withBOM` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) with BOM character. Defaults to `false`. ##### Transform Options See the [Duplex stream options](https://nodejs.org/api/stream.html#new-streamduplexoptions) for more details. ##### Async Options Options used by the underlying parsing library to process the binary or text stream. Not relevant when running in `objectMode`. Buffering is only relevant if you expect very large strings/numbers in your JSON. See [@streamparser/json](https://github.com/juanjoDiaz/streamparser-json#buffering) for more details about buffering. * `stringBufferSize` [<number>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) Size of the buffer used to parse strings. Defaults to 0 which means to don't buffer. Min valid value is 4. * `numberBufferSize` [<number>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) Size of the buffer used to parse numbers. Defaults to 0 to don't buffer. ### Complete Documentation See [https://juanjodiaz.github.io/json2csv/#/parsers/node-transform](https://juanjodiaz.github.io/json2csv/#/parsers/node-transform). ## Node Async Parser To facilitate usage, `NodeAsyncParser` wraps `NodeTransform` exposing a single `parse` method similar to the sync API. This method accepts JSON arrays/objects, TypedArrays, strings and readable streams as input and returns a stream that produces the CSV. `NodeAsyncParser` also exposes a convenience `promise` method which turns the stream into a promise that resolves to the whole CSV. ### Usage ```js import { AsyncParser } from '@json2csv/node'; const opts = {}; const transformOpts = {}; const asyncOpts = {}; const parser = new AsyncParser(opts, asyncOpts, transformOpts); const csv = await parser.parse(data).promise(); // The parse method return the transform stream. // So data can be passed to a writable stream (a file, http request, etc.) parser.parse(data).pipe(writableStream); ``` #### Parameters ##### Options * `ndjson` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) indicates that the data is in NDJSON format. Only effective when using the streaming API and not in object mode. * `fields` [<DataSelector[]>](/docs/advanced-options/data-selection.md) Defaults to toplevel JSON attributes. * `transforms` [<Transform[]>](/docs/advanced-options/transforms.md) Array of transforms to apply to the data. A transform is a function that receives a data recod and returns a transformed record. Transforms are executed in order. * `formatters` [<Formatters>](/docs/advanced-options/formatters.md) Object where the each key is a Javascript data type and its associated value is a formatters for the given type. * `defaultValue` [<Any>]() value to use when missing data. Defaults to `` if not specified. (Overridden by `fields[].default`) * `delimiter` [<String>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) delimiter of columns. Defaults to `,` if not specified. * `eol` [<String>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) overrides the default OS line ending (i.e. `\n` on Unix and `\r\n` on Windows). * `header` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) determines whether or not CSV file will contain a title column. Defaults to `true` if not specified. * `includeEmptyRows` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) includes empty rows. Defaults to `false`. * `withBOM` [<Boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean) with BOM character. Defaults to `false`. ##### Transform Options See the [Duplex stream options](https://nodejs.org/api/stream.html#new-streamduplexoptions) for more details. ##### Async Options Options used by the underlying parsing library to process the binary or text stream. Not relevant when running in `objectMode`. Buffering is only relevant if you expect very large strings/numbers in your JSON. See [@streamparser/json](https://github.com/juanjoDiaz/streamparser-json#buffering) for more details about buffering. * `stringBufferSize` [<number>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) Size of the buffer used to parse strings. Defaults to 0 which means to don't buffer. Min valid value is 4. * `numberBufferSize` [<number>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) Size of the buffer used to parse numbers. Defaults to 0 to don't buffer. ### Complete Documentation See [https://juanjodiaz.github.io/json2csv/#/parsers/node-async-parser](https://juanjodiaz.github.io/json2csv/#/parsers/node-async-parser). ## License See [LICENSE.md](https://github.com/juanjoDiaz/json2csv/blob/main/LICENSE.md). --- _Source: https://npm.io/package/@json2csv/node · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._