H.264 vs H.265: What Is the Difference?

H.264 and H.265 are video compression standards: rules for how an encoder shrinks raw video into a stream that can be sent over a network and stored, and how a decoder rebuilds it. Both were developed jointly by the ITU-T and ISO/IEC MPEG, which is why each has two names. H.264 is also called AVC, Advanced Video Coding, and was published in 2003. H.265 is also called HEVC, High Efficiency Video Coding, and was published in 2013 as its successor.

H.264 became the default codec for almost everything: IP cameras, video calls, Blu-ray, broadcast and the web. H.265 was designed to do the same job at roughly half the bitrate, mainly to make 4K and high-resolution surveillance practical. Our codec FAQ explains how video codecs work in general; this page compares these two in detail.

Both codecs work the same basic way. They split each frame into blocks, predict each block from nearby blocks or from earlier frames, and store only the difference. H.265 does each step more flexibly.

The table sets out the main differences. Real savings depend on the scene and the encoder settings.

Savings are largest at high resolutions and on static scenes, which is why H.265 suits fixed surveillance cameras so well. On low-resolution, high-motion video the gap narrows.

For recording, a lower bitrate means more days of footage on the same drives or more cameras on the same network. A camera streaming at 4 Mb/s around the clock writes roughly 43 GB a day. Halve the bitrate by switching to H.265 and the same drives keep footage for about twice as long, or the same retention needs about half the storage. Our bitrate FAQ shows how to work out file size from bitrate.

The saving also applies to the network. More camera streams fit on one PoE switch uplink or one cellular connection, which matters on vehicles and remote sites. Our guide to PoE in surveillance and NVR systems covers how that affects a whole system.

H.264’s biggest advantage is that almost everything can play it: every current browser, phone, smart TV, video management system and media player. H.265 support is good on hardware made in the last several years but less even in software. Browsers generally play HEVC only where the computer has a hardware decoder, and some older video management systems and web viewers cannot display it at all. Licensing is part of the reason. H.264 patents are largely handled by one pool, while HEVC patents are split across several pools and individual holders, which slowed its adoption in browsers and free software. Before switching a fleet of cameras to H.265, check that every viewer, recorder and analytics package in the chain decodes it.

H.265 takes considerably more processing than H.264, so real-time encoding and decoding at scale needs a hardware codec rather than the CPU. Most current options include both: NVIDIA GPUs and most Jetson modules have NVENC and NVDEC engines, Intel processors include Quick Sync Video, and IP cameras encode in a dedicated chip. It is worth checking the exact module, because the hardware differs. The Jetson Orin Nano, for example, has a hardware decoder but no hardware encoder.

Codec choice sets how much storage and decode power a recorder needs. Our video encoders and decoders include hardware H.264 and H.265 encoders, and our industrial NVRs record and analyse camera feeds in both formats. Our NVR FAQ covers the recorder itself.

We configure industrial NVRs and encoders with the codec, bitrate and storage set for each project as standard, and validate recording and playback before the system ships.