Click the 'Download' button next to the version you're interested in and the video will start to play. It's possible to download videos from Twitter at different resolutions, including 720p, 480p and 320p. You'll then see a list of possible video downloads. You can either right-click in this field and select 'Paste', or left-click and press Ctrl+V simultaneously. This done, move to the SaveTweetVid site and paste the URL into the box labelled 'Enter Twitter URL'. With the tweet open, highlight its URL in the address bar of your web browser and either right-click and select 'Copy', or press Ctrl + C simultaneously. This appears above the tweet, next to the username of the user who shared the video – it indicates how long ago the tweet was posted, so it could say anything from one minute to several days.
It's possible that you have watched videos in your Twitter timeline without clicking through to the actual tweet, and you can access this by either clicking the text of the tweet, or by clicking its timestamp. In order to download a video that's included in a tweet, you will need to known the URL of the tweet in question. SaveTweetVid is an online video downloader which you can use to save videos, GIFs and audio files that you find on Twitter.
