lingua-rs

Language detection for Node.js — wraps the lingua crate via N-API, detecting 75 languages with high accuracy using pre-trained statistical models.

Installation

npm install lingua-rs

Usage

import { detectLanguage, detectLanguageMany } from 'lingua-rs'

// Single text detection
const result = await detectLanguage(Buffer.from('This is clearly English text.'))
console.log(result.languages[0].iso6391)          // "en"
console.log(result.languages[0].iso6393)          // "eng"
console.log(result.languages[0].confidence)       // 0.9...
console.log(result.detector)                      // "lingua"
console.log(result.detectorModelVersion)          // "1.8.0"

// With options
const filtered = await detectLanguage(
  Buffer.from('Bonjour le monde.'),
  { minConfidence: 0.5 }
)

// Batch detection (processes all inputs in one libuv thread pool task)
const results = await detectLanguageMany([
  Buffer.from('The quick brown fox.'),
  Buffer.from('Bonjour le monde.'),
  Buffer.from('Hola mundo.'),
])

API

detectLanguage(input: Buffer, options?: DetectOptions): Promise<LinguaDetectionResult>

Detects the language(s) of a single UTF-8 encoded Buffer. Runs on the libuv thread pool — non-blocking.

detectLanguageMany(inputs: Buffer[], options?: DetectOptions): Promise<LinguaDetectionResult[]>

Detects languages for multiple inputs in a single thread pool task. More efficient than calling detectLanguage in a loop.

DetectOptions

Field	Type	Default	Description
lowAccuracy	boolean	false	Use the faster low-accuracy model
minConfidence	number	0.0	Filter out languages below this confidence threshold

LinguaDetectionResult

Field	Type	Description
detector	string	Always "lingua"
detectorModelVersion	string	Version of the lingua crate (e.g. "1.8.0")
languages	LanguageResult[]	Candidates sorted by descending confidence

LanguageResult

Field	Type	Description
iso6391	string	ISO 639-1 two-letter code (e.g. "en")
iso6393	string	ISO 639-3 three-letter code (e.g. "eng")
confidence	number	Score in [0.0, 1.0]

Repository layout

crate/      Pure-Rust library (the language detection logic, no napi deps)
package/    N-API cdylib + Node.js package (published to npm as lingua-rs)

License

MIT