The State of HEVC (H.265) Support

HEVC (High Efficiency Video Coding, or H.265) offers up to 50% better compression than H.264. Yet, trying to play an HEVC MP4 file in a web browser is a frustrating experience. Here is why.

The Licensing Nightmare

Unlike VP9 or AV1, which are royalty-free open standards, HEVC is encumbered by complex licensing patents held by multiple different patent pools (MPEG LA, HEVC Advance, Velos Media). To legally distribute a software decoder for HEVC, companies must pay hefty royalties.

Browser Vendor Approaches

• Apple (Safari): Apple is a patent holder and pays the royalties. Safari on macOS and iOS natively supports HEVC without issue, usually hardware-accelerated.
• Microsoft (Edge): Edge relies on the Windows OS. If the user has installed the "HEVC Video Extensions" from the Microsoft Store (sometimes costing $0.99), Edge can use it to hardware-decode HEVC.
• Google (Chrome): Google historically refused to pay HEVC royalties, pushing their own VP9/AV1 codecs. However, starting with Chrome 104, Google enabled HEVC support only if the underlying hardware provides the decoder. Chrome still does not ship a software fallback for HEVC.
• Mozilla (Firefox): Mozilla strongly opposes encumbered formats and refuses to ship HEVC support, pushing AV1 instead.

Conclusion: If you want guaranteed playback across all browsers, encode to H.264 or AV1. If you are in a pure Apple environment, HEVC is safe.