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>
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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");
});
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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?");  
})();
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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"});
})();
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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?");
})();
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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>
          ]
        }
     */
})();
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API

For the full documentation check out the API Documentation.

This library only supports promises.