Why animation costs energy
A still screen is cheap. Once nothing changes, the Mac can let the processor and graphics chip idle. An animation breaks that: every frame has to be calculated and composited onto the screen, and on displays that refresh up to 120 times a second, the work can add up.
The cost depends on three things:
- How much of the screen moves. A row of lights along the menu bar touches a thin strip. Full-screen snow touches everything.
- How often it updates. A gentle twinkle needs far fewer redraws than fast particle effects.
- Whether it ever stops. This is the big one.
The real question: does it pause?
Most of the time, decorations are not visible. Your windows cover the desktop, a video plays full screen, the lid is closed or the screen is locked. macOS tells apps when their windows are hidden or covered, and a well-written app uses that to stop drawing.
A badly written one keeps animating behind a full-screen video all afternoon, spending battery on frames nobody will ever see. That is where most of the drain from desktop decorations comes from.
Look for an app that pauses:
- when decorations are hidden;
- when the screen is locked or asleep;
- while a full-screen app covers the desktop.
How to check for yourself
Activity Monitor shows what each app costs:
- Open Activity Monitor (in Applications, then Utilities).
- Choose the Energy tab.
- Look at the Energy Impact column, which shows current consumption, and 12 hr Power, which averages over the last twelve hours.
- Compare the app while decorations are visible, then with a full-screen app covering them.
If the number drops close to zero when the decorations are covered, the app pauses properly. If it stays the same, it is drawing for nobody.
Settings that make a difference
- Fewer pets. Each pet is its own animation. Three cost less than twenty.
- Calmer light effects. A slow twinkle or steady glow is cheaper than a fast chase or sparkle.
- Lighter snow. Reduce the intensity, or let it snow only when the weather says so.
- A schedule. Decorations only in the evening means none at all during a working day on battery.
- Low Power Mode. On a MacBook, Low Power Mode in the Battery settings reduces energy use system-wide on long days away from a charger.
Is it worth worrying about?
For a well-behaved app with sensible settings, not much: the cost is in the same range as other small menu bar utilities. For an app that never pauses and runs full-screen effects all day, yes. The Energy tab answers the question in two minutes, for this or any other app. Our guide to what drains a Mac battery covers the other usual suspects.