Compared to an HD DVD, a Blu-ray disk offers higher storage capacity, faster reading and higher bit rate for videos and longer playback times. Although the two formats competed against one another in 2007, Blu-ray emerged as the preferred choice of customers. As such, manufacturers no longer produce HD DVD players.
For both formats, the exact capacity of a disk depends on the numbers of layers. A single-layer Blu-ray disk can store 25 gigabytes, and a single-layer HD DVD can hold 15 gigabytes. These numbers double on double layer disks. Furthermore, a BDXL disk can hold up to 128 gigabytes of data. BDXL is a more advanced version of Blu-ray.
Videos written to Blu-ray disks can be more detailed due to the higher bit rate that a Blu-ray disk can store. In comparison to HD DVD's combined video and audio maximum bit rate of 30.24 megabits per second, Blu-rays can go up to 48 megabits per second. This allows more visual and audio data to be transferred from the disc for each second of a movie.
When identical videos are saved to both disks, Blu-ray disks can store longer videos. While HD DVDs can only store 13.3 hours of video playback, videos saved on Blu-ray disks can be as long as 22.2 hours at 5 megabits per second.