An internet client-server method to rapidly preview video files. Source video files are compressed into lower resolution preview video files, thumbnail image files, and stored on a preview internet server. Typically only a small fraction of the source video frames, such as 1 frame in 60, is used for the preview. A user using a touch sensitive computerized device such as a smartphone can view the thumbnail video images while the compressed video files load in the background. When the user touches or swipes an image of interest, or shakes the device, device video preview application software detects the action and directs the device to start playing the preview video file(s). The application software detects when the user swipes the preview video, and changes the rate and direction of playback of the preview video file, and trickplay functionality, often according to the speed and/or direction of the swipe.