Welcome to the Google Duo Help CenterGet started with Google DuoSet up Google DuoTips for using Google DuoFind and invite contactsHelp make Google Duo betterMake video calls from Google Allo with DuoMake a callMake video calls with Google DuoPreview video calls with Knock KnockBlock numbers from calling you on Google DuoSee your video call while using another appLeave & check messages with Google DuoChange settingsLimit how much mobile data Google Duo usesSet phone to vibrate for callsStop getting Google Duo callsConnect a Google AccountDownload your call historyTroubleshoot issuesHow to send feedbackCan’t verify phone numberCan't find or sync contactsFix sound or video call problemsCall notifications aren't working