H.264 vs H.265 vs AV1

Released in 2003 and still the most compatible video codec ever made. Every phone, television, browser, editor and set-top box decodes it in hardware. If a video has to play somewhere you do not control, this is the answer and the decision takes no thought.

The cost is efficiency: at the same visible quality it produces the largest files of the three. For a short clip that is irrelevant. For a two-hour film it is gigabytes.

HEVC delivers roughly the same quality in 30 to 50 per cent less space, which is why phones record in it and why streaming services adopted it. It is also why an iPhone video sometimes will not play on a Windows laptop: the patent licensing that pays for HEVC has kept it out of some software entirely.

Use it when you control the players — your own devices, an Apple-only workflow, a home media library. Avoid it for anything you are sending to someone whose setup you do not know.

AV1 is royalty-free and more efficient than HEVC, particularly at low bitrates, which is where streaming platforms care most. YouTube, Netflix and others serve it widely.

Two practical catches. Encoding is slow — dramatically so compared with H.264 — which matters when you are converting your own files rather than running a datacenter. And hardware decoding only arrived in devices from roughly 2020 onwards; on older hardware playback falls back to software and drains the battery.

Ask where the file is going. Somewhere you do not control — H.264 in an MP4, without exception. Your own devices or a media library — HEVC, for the storage saving. Your own website, with a fallback — AV1 or VP9 in WebM, alongside an H.264 MP4 for everything else.

Bitrate matters more than codec choice for how a video looks. A generously encoded H.264 file beats a starved AV1 one every time. If a video needs to reach a specific size, Compress Video works backwards from that number instead of making you guess at settings.