The successor to H.264
High Efficiency Video Coding (HEVC) is a video compression standard finalised in 2013. It was developed by the same two standards bodies behind H.264, the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group, and it has two official names: H.265 and MPEG-H Part 2. People use “HEVC” and “H.265” interchangeably.
The development goal was often described as reaching the same visual quality as H.264 with roughly half the bitrate, particularly for high-resolution video. Real-world savings vary with content, encoder and settings, and they are usually smaller than that headline target at lower resolutions. A saving of a third to a half is a commonly cited range in the right conditions, but treat it as a rough guide rather than a promise.
How HEVC improves efficiency
HEVC uses the same overall approach as other modern codecs (spatial and temporal prediction, a transform, quantisation and entropy coding): predict each block from elsewhere, store the difference, transform it and discard what is least visible. It changes the building blocks to work better at high resolutions.
- Larger, more flexible blocks. H.264 splits the picture into small fixed-size macroblocks. HEVC uses coding tree units up to 64 by 64 pixels that can be subdivided as needed. Large blocks handle smooth areas of a 4K frame efficiently, while subdivision preserves detail where it exists.
- More prediction options. HEVC offers many more directions for predicting a block from its neighbours within a frame, which helps with diagonal edges and textures.
- Improved motion prediction. Better ways of signalling and predicting movement reduce the data needed to describe objects that move between frames.
- Additional filters. In-loop filters reduce blocking and ringing, including one that adjusts sample values to better match the original.
- Parallel processing features. The design includes tools that let encoders and decoders split work across several processor cores, which becomes more important as resolution increases.
All of this costs computation. HEVC encoders are generally slower than H.264 encoders, and decoders need more processing power or dedicated hardware.
Where HEVC is used
HEVC became common wherever resolution and bitrate pressure are high:
- 4K and ultra-high-definition broadcast and discs. Its efficiency suits 4K video, and it is closely associated with high dynamic range and wide colour delivery. Those formats depend on high dynamic range signalling and wider color spaces, which need more bit depth.
- Many phones and cameras, which record HEVC to reduce file sizes at high resolutions.
- Some streaming services and set-top devices, particularly for premium high-resolution content.
- Video editing workflows, where HEVC files from cameras may need conversion or hardware support to play smoothly.
Hardware decoding is widely present in recent phones, computers and televisions. Older devices may lack it, which is a frequent source of “this video will not play” issues, in part because the file sits inside a container that the device does understand while the codec inside is not supported.
The licensing complication
The most distinctive part of HEVC’s story is not technical. H.264 was licensed mainly through a single patent pool. For HEVC, the patent landscape became more fragmented. Several separate pools and licensing arrangements emerged, along with some rights holders who preferred to license on their own, and the terms were not always aligned or easy to compare.
The consequences, as commonly described, were:
- Uncertainty for implementers. Companies shipping products or services needed to work out which licences applied, and what the cumulative cost might be.
- Slower adoption in some areas. Browsers and web platforms were cautious, and support for HEVC playback in web browsers has been uneven and dependent on the operating system or hardware.
- Motivation for alternatives. The licensing complexity was one of the reasons companies pushed for royalty-free options, which led to the AV1 codec, alongside Google’s earlier work on VP9.
Specific fees and terms change and are different for different kinds of products, so they are not covered here. If you are building a product or service that includes HEVC, check the current terms and consider professional advice. Rules vary by country, and this article is general information, not legal advice.
HEVC versus other codecs
- Versus H.264. HEVC is typically more efficient, especially at 1080p and above, but it is less universally supported and slower to encode.
- Versus VP9. Both aim at similar efficiency goals. Results are generally close, though the better choice depends on the content and encoder, and on which platform and devices are involved.
- Versus AV1. AV1 is often reported to be somewhat more efficient than HEVC, at the cost of heavier encoding and still-growing hardware support.
A newer successor standard, Versatile Video Coding (VVC, or H.266), was finalised in 2020 and targets further savings. Its adoption is still developing and how widely it will be used is uncertain.
Practical advice
For compatibility, H.264 remains the safer default. HEVC is a reasonable choice when file size matters, when you work in 4K, or when your camera records it natively and you know your editing hardware handles it. If a file stutters in an editor, converting to an editing-friendly format, or using proxy files, is a common fix, and the cause is usually decoding load rather than a problem with the footage.
When publishing, remember that many platforms re-encode uploads, so the format you upload does not always determine what viewers receive.