YouTube predominantly utilizes the H.264 video compression standard. This is a widely supported codec, also known as Advanced Video Coding (AVC). It allows for efficient encoding and decoding of video content, resulting in relatively small file sizes without significant loss of visual quality. For example, a user uploading a video file encoded with H.264 will generally find it readily processed and available for viewing on the platform.
The widespread adoption of H.264 is beneficial because it strikes a balance between video quality and file size. This balance ensures relatively fast upload times for content creators and smooth playback experiences for viewers, even on devices with limited bandwidth. Historically, this codec became a standard choice due to its compatibility across a broad range of devices and its ability to provide good compression compared to older formats.