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jeffsbaker's avatar
jeffsbaker
Tin Contributor
Jul 18, 2026

Edge version 150 JavaScript speechSynthesis.getVoices() undefined voices

For the past few days JavaScript speechSynthesis has had a problem in Edge browser. Sometimes it gets the proper list of voices but most of the time it returns: "Microsoft undefined Online (Natural) ...
edge
javascript
speech synthesis
Text to Speech
voices
Jamony's avatar
Jamony
MCT
Jul 19, 2026

You’re reproducing an intermittent Edge 150 issue where Natural voice entries contain undefined fields and speech then falls back to Microsoft David. Microsoft’s Edge known-issues page does not list this symptom, so treat it as an unconfirmed regression, not a documented outage.

 

First open edge://settings/help, install any available update, restart Edge, and retest the minimal page. Test once in InPrivate with no extensions allowed. On a managed device, open edge://policy and check ConfigureOnlineTextToSpeech; Microsoft documents that disabling it makes online voice fonts unavailable. Capture successful and failing getVoices() results in DevTools Console, including name, lang, voiceURI, localService, timestamp, Windows build, and Edge version.

 

A community reply cannot ship the fix. Press Alt+Shift+I, describe the expected and actual arrays, include the minimal reproduction, and leave diagnostic data enabled. Meanwhile, reject incomplete voice entries and use a confirmed local voice fallback when an entry is incomplete.