Wallpaper resolution advice usually skips the part that matters on a Mac: the number in System Settings is a *scaled* resolution, not the panel's real pixel count. Target the physical pixels and everything looks right. For the exact pixel dimensions of every MacBook, iMac, and Apple display, see MacBook wallpaper size.
Retina scaling in one paragraph
A 14-inch MacBook Pro may report a "looks like 1512×982" desktop while the panel is 3024×1964 physical pixels. macOS renders at the higher resolution and scales down, which is what makes text crisp. Your wallpaper should match the physical pixels, 3024×1964 here, not 1512×982.
Targets that cover most Macs
- MacBook Air / Pro (Retina): 3024×1964 or 3456×2234 depending on the model.
- 4K external display: 3840×2160.
- 5K display (Studio Display, iMac 27-inch): 5120×2880.
- Ultrawide 34-inch: 3440×1440.
- Vertical / rotated panel: swap the axes, e.g. 2160×3840.
- When in doubt: 3840×2160. It downscales cleanly to almost everything.
Aspect ratio beats pixel count
A resolution mismatch is only a scaling operation. An aspect ratio mismatch means cropping: a 16:9 loop on a 21:9 ultrawide loses the top and bottom, or gets stretched. Prefer footage in your display's shape, and keep the subject of the shot away from the edges so a crop stays survivable.
Multiple displays
- One loop mirrored: decoded once and drawn on each display. Cheapest option by a wide margin.
- A different loop per display: decoded once per unique video. Three 4K loops means three times the decode work.
- Mixed resolutions: encode for the largest panel and let macOS scale down for the rest. Upscaling looks worse than downscaling.
- Vertical secondary display: give it a dedicated portrait loop rather than cropping a landscape one.
On a laptop driving two external panels, mirroring one loop is the difference between a wallpaper you never notice and one you do. Per-display setup lives in set a live wallpaper.
Legibility, not just sharpness
- Keep the top-left quiet, because that is where desktop icons and their labels sit.
- Avoid bright moving highlights near the menu bar, which is translucent.
- Low-contrast footage is the practical choice for a wallpaper you work in front of all day.
Keep learning
- What is a live wallpaper?A live wallpaper is a short video loop rendered at the desktop wallpaper layer instead of a still image.
- How macOS wallpapers workmacOS composites the wallpaper as its own layer below icons and windows, and only recent versions let third-party apps supply Lock Screen video.
- Hardware video decodeApple's media engine can decode supported H.264 and HEVC video in dedicated hardware, reducing the CPU work required for a 4K wallpaper loop.
- Video formats and codecsEncode wallpapers as H.264 or HEVC in an MP4 container, at display resolution, 24–30 fps, with no audio track.
- Battery and energy basicsA wallpaper's battery cost is decode work times time on screen, so pausing when nothing is visible removes almost all of it.