Video formats and codecs, explained for wallpapers

Two things get conflated constantly. The container is the file wrapper: `.mp4`, `.mov`, `.mkv`, `.webm`. The codec is how the picture inside is compressed: H.264, HEVC, ProRes, AV1, VP9. The extension tells you the container; it does not tell you the codec, and the codec is what determines whether your Mac decodes efficiently.

Containers you will meet

• •MP4: the universal choice. Broad support, small overhead, works everywhere.
• •MOV: Apple's container. Functionally similar to MP4 and the default from Final Cut and QuickTime.
• •M4V: an MP4 variant from the Apple ecosystem.
• •MKV: flexible and popular for archiving, but the least predictable for native macOS playback.
• •WebM: a web container, usually carrying VP9 or AV1. Poor fit for macOS wallpapers.

Codecs, ranked for this job

1. HEVC (H.265): best size-to-quality ratio, hardware decoded on modern Macs. First choice.
2. H.264 (AVC): slightly larger at equal quality, hardware decoded on everything. Safest choice.
3. ProRes: beautiful and enormous. Fine as a master, wasteful as a wallpaper.
4. AV1: excellent compression, but hardware decode only on the newest Apple silicon.
5. VP9: typically software decoded on macOS. Avoid.

Export recipe for a wallpaper

• •Container: MP4.
• •Codec: HEVC, or H.264 if you want maximum compatibility.
• •Resolution: match your display, 3840×2160 for a 4K panel. Never encode above it.
• •Frame rate: 24–30 fps. Ambient motion gains nothing from 60.
• •Bitrate: 8–15 Mbps at 4K is plenty for the slow footage that makes good wallpaper.
• •Colour: Rec. 709, SDR. HDR wallpapers can look washed out or oddly bright next to standard UI.
• •Audio: remove the track entirely.
• •Duration: 5–30 seconds, looping cleanly.

Making the loop seamless

1. Pick footage with no strong directional change: drifting fog, rain, gentle particle motion, slow pans.
2. Trim so the first and last frames are visually close.
3. Crossfade the final half-second into the opening half-second, or mirror the clip for a ping-pong loop.
4. Preview it looping for a full minute before you commit. Loop points you barely notice once become obvious after ten repeats.

Ready to use your own file? Import your own videos walks through the drag-and-drop flow.