AV1, HEVC and why streaming services carry more than one codec
Two codecs do roughly the same job, and services publish in both. The reason is only partly technical — and which one reaches your screen is decided by the chip inside your device.
A large streaming service will encode the same title several times over, in more than one codec, and store all of it. That is expensive, and services do not do expensive things by accident. The reason two modern codecs coexist is a mix of engineering and licensing, and it has a direct consequence for what your device gets served.
What a newer codec buys
Each generation of video codec delivers roughly comparable picture quality in fewer bits than the last. Less data per second means lower delivery costs for the publisher and a better chance of a stable stream for the viewer — the same picture arriving over a weaker connection.
| Codec | Roughly | The catch |
|---|---|---|
| H.264 / AVC | The long-standing baseline | Plays almost everywhere; needs the most bandwidth |
| HEVC / H.265 | Substantially more efficient | Licensing is fragmented across multiple patent pools |
| AV1 | More efficient again, royalty-free | Needs a hardware decoder; older devices cannot play it well |
Why AV1 exists at all
HEVC is a capable codec with an awkward commercial history. Its patent licensing ended up spread across several separate pools with different terms, which made the total cost and legal position hard for a large distributor to establish with confidence.
AV1 was developed by the Alliance for Open Media, a consortium whose membership includes the largest video distributors and several chip manufacturers, and it is published on royalty-free terms. That is the decisive difference for anyone shipping billions of hours of video: the licensing question simply does not arise.
Hardware decoding is the real constraint
A codec is only useful if the device at the other end can decode it. Modern codecs are computationally heavy, and a television or streaming stick decodes them in a dedicated block of silicon rather than in general-purpose software.
If that block does not support a codec, the device either falls back to software decoding — which on low-power hardware often means dropped frames — or the service simply serves it something else. This is why codec support is a fixed property of the hardware you own and cannot be added by an update, and it is one of the differences that distinguishes streaming platforms from one another.
Where the transition has reached
Industry reporting through 2025 and into 2026 describes AV1 moving from an experiment to a default on the largest platforms, with a substantial share of Netflix traffic and the majority of YouTube playback delivered in AV1 where the device supports it. Device support has followed: hardware AV1 decoding is now common in televisions and streaming devices sold in recent years, and in current phone and computer silicon.
The two figures worth holding onto are less precise but more durable. First, a device bought in the last two or three years probably decodes AV1. Second, one bought before that probably does not, and never will.
What this means for a viewer
- You do not choose the codec. The service and your device negotiate it. There is no setting.
- An older device is not broken. It receives an older codec, which needs more bandwidth for the same picture. On a good connection you may never notice.
- Codec support is worth checking before buying, particularly on inexpensive streaming sticks, where it is one of the few specifications that genuinely constrains what you can watch.
- A service dropping an old codec is the real risk. It is rare and slow, but it is the mechanism by which a working device eventually stops working.
Where codecs sit in the wider delivery chain is covered in how streaming video reaches your TV. Terms are defined in the glossary.
Sources and further reading
- Alliance for Open Media — AV1 and the AOMedia licensing position · The consortium behind AV1 and its royalty-free terms
- Streaming Media — The State of Streaming Codecs 2026 · Industry survey of current codec deployment
- ScientiaMobile — AV1 Codec Hardware Decode Adoption · Device-level measurement of hardware AV1 decoding
Written by
MobilizedTV Editorial Team
MobilizedTV is written and edited as a single publication rather than by named individual contributors. How we research, source and correct our work is set out in the editorial policy.
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