YouTube employs a variety of video file types for content delivery. The specific encoding used depends on factors such as resolution, upload date, and playback device. Common formats include MP4 (MPEG-4 Part 14), which typically uses H.264 video codec and AAC audio codec. Older content may utilize FLV (Flash Video), though its prevalence has diminished due to HTML5 advancements. Adaptive bitrate streaming allows YouTube to dynamically adjust video quality based on network conditions, further influencing the specific file format delivered.
The choice of video format directly impacts video quality, file size, and compatibility. Efficient encoding results in smaller file sizes, reducing bandwidth consumption and improving streaming performance. Widespread codec support ensures playback across diverse platforms and devices. The evolution of video encoding technologies has facilitated higher resolution streaming and more efficient compression, enhancing the viewing experience while minimizing infrastructure demands.