What size of bandwidth required to transmit and play video online?

The bandwidth required to transmit and play video online varies based on the video quality. For standard definition (SD) video, about 3-4 Mbps is typically sufficient, while high definition (HD) video requires around 5-8 Mbps. For 4K ultra-high definition (UHD) video, the requirement can increase to 25 Mbps or more. It's essential to consider that these figures can vary depending on compression methods and streaming platforms.