What is x265, H.265 or HEVC? 1.x265: x265 is a video encoder application library, designed to encode video or images into the H.265 /HEVC video compression format. 2.HEVC/H.265: HEVC (High Efficiency Video Coding), also known as H.265 or MPEG-H Part 2, is a video compression standard, the most popular successor to the widely used AVC (H.264 or MPEG-4 Part 10). HEVC is widely used in ultra HD video compression, up to 8K UHD.So their relationship is: x265 – H.265 (HEVC), x264 – H.264 (AVC). Talking about converting x265 to MP4, we normally mean converting HEVC/H.265 video to MP4. Why Convert x265/HEVC/H.265 to MP4? x265 is judged best overall HEVC encoder specialized in encoding high quality HEVC/H.265 videos. Users can utilize x265 to encode HEVC/H.265 videos which are twice compressed than H.264/x264 videos. To be more specific, to achieve same video quality, x265/HEVC encoding offers double data compression at half bit rate of x264/AVC encodi...