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Google Cloud Speech API: Node.js Client

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Node.js idiomatic client for Speech API .

Client API Reference


Before you begin

  1. Select or create a Cloud Platform project.

    Go to the projects page

  2. Enable billing for your project.

    Enable billing

  3. Enable the Google Cloud Speech API API.

    Enable the API

  4. Set up authentication with a service account so you can access the API from your local workstation.

Installing the client library

npm install --save @google-cloud/speech

Using the client library

// Imports the Google Cloud client library
const speech = require('@google-cloud/speech');
const fs = require('fs');

// Your Google Cloud Platform project ID
const projectId = 'your-project-id';

// Creates a client
const client = new speech.SpeechClient({
  projectId: projectId,

// The name of the audio file to transcribe
const fileName = './resources/audio.raw';

// Reads a local audio file and converts it to base64
const file = fs.readFileSync(fileName);
const audioBytes = file.toString('base64');

// The audio file's encoding, sample rate in hertz, and BCP-47 language code
const audio = {
  content: audioBytes,
const config = {
  encoding: 'LINEAR16',
  sampleRateHertz: 16000,
  languageCode: 'en-US',
const request = {
  audio: audio,
  config: config,

// Detects speech in the audio file
  .then(data => {
    const response = data[0];
    const transcription = response.results
      .map(result => result.alternatives[0].transcript)
    console.log(`Transcription: ${transcription}`);
  .catch(err => {
    console.error('ERROR:', err);


Samples are in the samples/ directory. The samples' has instructions for running the samples.

Sample Source Code Try it
Speech Recognition source code Open in Cloud Shell

The Speech API Node.js Client API Reference documentation also contains samples.


This library follows Semantic Versioning .

This library is considered to be General Availability (GA) . This means it is stable; the code surface will not change in backwards-incompatible ways unless absolutely necessary (e.g. because of critical security issues) or with an extensive deprecation period. Issues and requests against GA libraries are addressed with the highest priority.

More Information: Google Cloud Platform Launch Stages


Contributions welcome! See the Contributing Guide .


Apache Version 2.0