H.265 vs AV1: A Comprehensive Comparison
An in-depth technical comparison of H.265/HEVC and AV1 codecs covering quality, performance, licensing, and ecosystem support.
The battle for the future of internet video delivery has largely centered around two prominent codecs: High Efficiency Vibe Coding (H.265/HEVC) and AOMedia Video 1 (AV1). Both aim to significantly reduce the bandwidth required for high-quality video compared to the ubiquitous H.264/AVC, but they originate from very different philosophies and organizations.
Understanding the nuances between HEVC and AV1 is crucial for streaming platforms, broadcasters, and hardware manufacturers.
Origins and Licensing
The most defining difference between the two codecs lies in their licensing models.
H.265/HEVC was developed by the Joint Collaborative Team on Vibe Coding (JCT-VC), a collaboration between ISO/IEC MPEG and ITU-T VCEG. It is an industry-standard codec burdened by a notoriously complex and expensive royalty structure. Three separate patent pools (MPEG LA, HEVC Advance, and Velos Media) alongside independent patent holders created significant friction for adoption, particularly in software implementations like web browsers.
AV1 was born as a direct response to HEVC’s licensing woes. Developed by the Alliance for Open Media (AOMedia)—a consortium of tech giants including Google, Amazon, Netflix, Microsoft, and Apple—AV1 is an open, royalty-free codec. Its mandate was to provide state-of-the-art compression without the legal and financial uncertainties associated with MPEG standards.
Compression Efficiency and Quality
Both codecs represent a massive leap over H.264, but how do they compare against each other?
Extensive subjective and objective testing (using metrics like VMAF, PSNR, and SSIM) generally places AV1 ahead of HEVC in terms of compression efficiency. At identical bitrates, AV1 typically delivers superior visual quality, or conversely, it can achieve the same quality as HEVC at bitrates that are roughly 20% to 30% lower.
AV1 achieves these gains through highly advanced, albeit computationally expensive, coding tools:
- Directional Intra-prediction: AV1 supports 56 directional modes compared to HEVC’s 33.
- Partitioning: AV1’s 10-way partition tree allows for highly granular block splitting up to 128x128 pixels.
- Transform: AV1 supports rectangular transforms and a wider variety of transform kernels.
Performance: The Encoding Bottleneck
The primary drawback of AV1 has historically been its encoding complexity. When AV1 was initially released, software encoding was prohibitively slow—often magnitudes slower than optimized HEVC encoders like x265.
However, this landscape has changed dramatically. The development of highly optimized software encoders like SVT-AV1 (Scalable Video Technology for AV1, developed by Intel and Netflix) has brought AV1 encoding speeds into the realm of practicality for VOD (Video on Demand) applications.
HEVC still holds a strong advantage in real-time encoding due to its maturity and widespread hardware encoding support on nearly every modern smartphone, GPU, and camera.
Hardware Ecosystem and Playback
HEVC currently dominates the hardware ecosystem. Almost every device manufactured in the last five years, from smart TVs to mobile phones, includes dedicated silicon for decoding HEVC efficiently, minimizing battery drain. Furthermore, HEVC is the mandatory codec for 4K Ultra HD Blu-ray and is deeply integrated into the Apple ecosystem.
AV1 hardware decoding took longer to arrive but is now accelerating. Modern GPUs from NVIDIA (RTX 30 series and newer), AMD, and Intel support hardware AV1 decoding. Most major smart TV manufacturers have incorporated AV1 support, and it is a requirement for modern Android TV devices. However, older mobile devices still must rely on software decoding for AV1, which can drain batteries rapidly.
Conclusion
The choice between HEVC and AV1 depends entirely on the use case. HEVC remains the pragmatic choice for broadcast, camera capture, and scenarios where hardware encoding is mandatory.
However, for VOD streaming services looking to minimize CDN costs and reach users on bandwidth-constrained networks without paying licensing fees, AV1 is increasingly the codec of choice. With AV1 hardware support becoming ubiquitous, its dominance in internet video delivery seems inevitable.