ReadAloud stores playback preferences, the selected voice, overlay position, and Google connection state in Firefox extension storage. When a user connects Google and chooses a Google Cloud voice, ReadAloud sends the text being read, including SSML used for highlighting, to Google Cloud Text-to-Speech so Google can return audio. The Google OAuth access token is sent to Google for authentication, and the Google account email returned by Google is stored locally so the extension can show which account is connected. When a built-in Firefox voice is selected, the text stays in Firefox and is not sent to an external speech service. ReadAloud has no analytics, advertising, or background telemetry. Users can disconnect Google and use a built-in Firefox voice when they do not want page text sent to Google.