H.265, also known as HEVC (High Efficiency Video Coding), is the successor to H.264 developed by ITU-T in 2013. H.265 achieves approximately 40-50% better compression efficiency than H.264 — meaning a video at the same visual quality occupies roughly half the storage space. This efficiency gain comes from larger coding units (up to 64×64 pixels vs H.264's 16×16), more prediction modes, and improved motion compensation.
H.265 is the standard codec for 4K UHD content — streaming services like Netflix use H.265 for 4K delivery, and most modern smartphones record 4K in H.265 (Apple calls it HEVC). Hardware decoding support is widespread in devices manufactured after 2015. However, software decoding of H.265 is computationally intensive and may struggle on older devices.
For sharing, H.264 remains the safer compatibility choice — some older phones, TVs, and web browsers can't handle H.265 without hardware support. For personal archiving or transfer between modern devices, H.265 is excellent: better quality or smaller file size. FileCurve currently encodes using H.264 for maximum compatibility.