A comparison of the two most widely used video codecs, where H.265 offers better compression at the cost of compatibility and encoding speed.
H.264 (also called AVC) and H.265 (also called HEVC) are two generations of the same video compression standard. H.265 is the successor, achieving roughly 50% better compression than H.264 at the same visual quality — meaning a file that is half the size or the same size with noticeably better quality. The tradeoff is that H.265 requires more processing power to encode and decode, and its licensing is more complex.
Both codecs work by dividing video frames into blocks and using prediction to minimize redundant data. The key difference is block size and prediction sophistication. H.264 uses macroblocks up to 16x16 pixels, while H.265 uses coding tree units up to 64x64 pixels. Larger blocks mean the codec can more efficiently compress large uniform areas (like a sky or a wall) while still using small blocks for detailed regions.
H.265 also has more advanced motion prediction, better in-loop filtering to reduce artifacts, and improved entropy coding. All of these improvements add up to significantly better compression, but they also mean the encoder and decoder must do more work per frame.
In practice, H.264 remains the safe default for web video because of its universal support. Every browser, device, and hardware decoder supports H.264. H.265 support is widespread but not universal — some browsers require specific conditions or OS support. Newer codecs like AV1 promise H.265-level compression with royalty-free licensing, but hardware support is still catching up.
The choice between H.264 and H.265 affects bandwidth costs, storage requirements, and device compatibility. For platforms serving large volumes of video, the 50% compression improvement of H.265 can translate to significant cost savings on CDN bandwidth. But if your audience includes older devices or browsers without H.265 support, you need to serve H.264 as a fallback anyway.
For most businesses, the practical answer is to let your hosting platform handle codec selection. The platform can encode in multiple codecs and serve the most efficient option each viewer's device supports.
host.video manages codec selection automatically during transcoding, optimizing for the best combination of compression efficiency and device compatibility so you never need to choose between H.264 and H.265 yourself.