MsEdgeTTS

[Update Dec 2025]
The Read Aloud API now requires a user agent matching the Microsoft Edge browser, and thus will not work in browsers other than Microsoft Edge. It will of course still work in any server-side runtime.

A simple Azure Speech Service module that uses the Microsoft Edge Read Aloud API.

~~Full support for SSML~~ Only supports speak, voice, and prosody element types. The following is the default SSML object:

<speak version="1.0" xmlns="http://www.w3.org/2001/10/synthesis" xmlns:mstts="https://www.w3.org/2001/mstts"
       xml:lang="${this._voiceLang}">
    <voice name="${voiceName}">
        <prosody rate="${rate}" pitch="${pitch}" volume="${volume}">
            ${input}
        </prosody>
    </voice>
</speak>

Documentation on the SSML format can be found here . All supported audio formats can be found here.

Example usage

Make sure to escape/sanitize your user's input! Use a library like xml-escape.

Write to stream

import {MsEdgeTTS, OUTPUT_FORMAT} from "msedge-tts";

const tts = new MsEdgeTTS();
await tts.setMetadata("en-IE-ConnorNeural", OUTPUT_FORMAT.WEBM_24KHZ_16BIT_MONO_OPUS);
const {audioStream} = tts.toStream("Hi, how are you?");

audioStream.on("data", (data) => {
    console.log("DATA RECEIVED", data);
    // raw audio file data
});

audioStream.on("close", () => {
    console.log("STREAM CLOSED");
});

Write to file

import {MsEdgeTTS, OUTPUT_FORMAT} from "msedge-tts";

(async () => {
    const tts = new MsEdgeTTS();
    await tts.setMetadata("en-US-AriaNeural", OUTPUT_FORMAT.WEBM_24KHZ_16BIT_MONO_OPUS);
    const {audioFilePath} = await tts.toFile("./tmpfolder", "Hi, how are you?");  
})();

Change voice rate, pitch and volume

import {MsEdgeTTS, OUTPUT_FORMAT} from "msedge-tts";

(async () => {
    const tts = new MsEdgeTTS();
    await tts.setMetadata("en-US-AriaNeural", OUTPUT_FORMAT.WEBM_24KHZ_16BIT_MONO_OPUS);
    const {audioStream} = await tts.toStream("Hi, how are you?", {rate: 0.5, pitch: "+200Hz"});
})();

Use an alternative HTTP Agent

Use a custom http.Agent implementation like https-proxy-agent or socks-proxy-agent.

import {MsEdgeTTS, OUTPUT_FORMAT} from "msedge-tts";
import {SocksProxyAgent} from 'socks-proxy-agent';

(async () => {
    const agent = new SocksProxyAgent("socks://your-name%40gmail.com:abcdef12345124@br41.nordvpn.com")
    const tts = new MsEdgeTTS(agent);
    await tts.setMetadata("en-US-AriaNeural", OUTPUT_FORMAT.WEBM_24KHZ_16BIT_MONO_OPUS);
    const {audioStream} = await tts.toStream("Hi, how are you?");
})();

Get sentence and word boundaries

import {MsEdgeTTS, OUTPUT_FORMAT} from "msedge-tts";

(async () => {
    const tts = new MsEdgeTTS();
    await tts.setMetadata("en-US-AriaNeural", OUTPUT_FORMAT.WEBM_24KHZ_16BIT_MONO_OPUS, {
        wordBoundaryEnabled: true,
        sentenceBoundaryEnabled: true
    });
    // as stream
    const {metadataStream} = await tts.toStream("Hi, how are you doing today hello hello hello?");
    /* ->
        {
          "Metadata": [
            {
              "Type": "SentenceBoundary",
              "Data": {
                "Offset": 1000000,
                "Duration": 35875000,
                "text": {
                  "Text": "Hi, how are you doing today hello hello hello?",
                  "Length": 46,
                  "BoundaryType": "SentenceBoundary"
                }
              }
            }
          ]
        }
     */
    // or as file
    const {metadataFilePath} = await tts.toFile("Hi, how are you?");
    /* ->
       {
          "Metadata": [
            <all metadata combined>
          ]
        }
     */
})();

API

For the full documentation check out the API Documentation.

This library only supports promises.