Welcome to Android Central! How are you sending the video -- via the stock Messaging app? Sending video as an MMS message is never a good idea, because the maximum attached filesize for MMS is about 1 MB. Compressing a video down to 1 MB makes it look terrible. It's better to upload the video somewhere (like your Google Photos in the cloud, or YouTube), and then share the link privately. Or, if you and the recipient both use an alternate messaging platform that handles videos better (like Telegram), use that.
09-11-2018 11:35 PM