How to speed up a slow Mac

If your Mac feels sluggish — windows that drag open, a Dock that bounces lazily, a login that takes forever — the cause is usually one of four things: UI animations chewing GPU time, transparency effects sampling the desktop constantly, too many apps at startup, or background processes keeping memory pressure high. All of them are fixable.

Why Macs feel slow over time

Apple's default macOS settings prioritize looking polished over feeling instant. Every window that opens plays an animation. The menu bar and Dock blur whatever is behind them in real time. Mission Control fans out with a choreographed sweep. On a new M-series Mac these effects are nearly free. On an older Intel machine, or when memory pressure is high, they create visible lag.

The good news: every one of these is a software setting, not a hardware limit. Turning them off reclaims GPU headroom and makes the system feel snappier immediately.

1. Disable window open/close animations

The biggest perceived speed win is disabling the animation that plays when windows open, close, or minimize. Open Terminal and run:

# windows open and close instantly
defaults write NSGlobalDomain NSAutomaticWindowAnimationsEnabled -bool false

No restart needed — new windows open instantly from this point. To also speed up panel and sheet animations (like Save dialogs dropping down):

# make sheet animations near-instant
defaults write NSGlobalDomain NSWindowResizeTime -float 0.001

To undo either setting later, replace -bool false with -bool true, or delete the key with defaults delete NSGlobalDomain NSAutomaticWindowAnimationsEnabled.

2. Speed up the Dock

If you have Dock auto-hide turned on, the default slide-in animation takes about 0.5 seconds — noticeable every time you reach for it. Drop it to 0.15 seconds:

# faster Dock slide animation
defaults write com.apple.dock autohide-time-modifier -float 0.15 && killall Dock

While you're there, stop the app-launch bounce, which adds visible delay to every app open:

# disable the Dock launch bounce
defaults write com.apple.dock launchanim -bool false && killall Dock

3. Speed up Mission Control

The fan-out animation when you press F3 or swipe up with three fingers defaults to around 0.5 seconds. Cutting it to 0.1 seconds makes the transition feel immediate:

# faster Mission Control animation
defaults write com.apple.dock expose-animation-duration -float 0.1 && killall Dock

4. Reduce transparency

The frosted-glass effect on the menu bar, Dock, sidebar, and notification center constantly samples and blurs whatever is behind them. On older or memory-pressured machines this is a real cost. Turn it off in System Settings > Accessibility > Display and enable Reduce Transparency.

You'll notice the menu bar and Dock turn opaque — a small visual trade-off for a noticeably sharper feel. You can also enable Reduce Motion on the same screen, which stops the parallax effect and cross-fade transitions.

5. Trim login items

Every app that launches at startup competes for CPU and RAM during the first minute after login. Open System Settings > General > Login Items & Extensions. The upper section shows apps that open on login — remove anything you don't need open immediately. The lower section shows background items (helpers, menu-bar agents) — scrutinize these too, since they run invisibly all day.

Some apps re-add themselves after updates, so it's worth checking this list every few months.

6. Check memory pressure in Activity Monitor

Open Activity Monitor (Applications > Utilities), click the Memory tab, and look at the Memory Pressure graph at the bottom. Green means you're fine. Yellow means the system is managing actively. Red means macOS is compressing memory and potentially swapping — and the fix there is to close apps, not adjust settings.

Sort the process list by Memory to find what's consuming the most. Browser tabs are a common culprit: each open tab in Chrome or Firefox is its own process.

Stop apps from reopening after restart

macOS asks if you want to reopen windows when you restart. If you say yes, every app that was open relaunches automatically — which slows the next login considerably. To stop this, uncheck "Reopen windows when logging back in" in the restart dialog, or go to System Settings > Desktop & Dock and disable Close windows when quitting an application (this controls session restore behavior).

For a more targeted fix: hold Shift while clicking your username at the login screen to suppress login items and window restore for that session only.

Reduce Motion for accessibility-driven speed

If you haven't already, enabling Reduce Motion in Accessibility kills the zoom animation when you switch between apps and desktops, replacing it with a faster cross-fade. It's one of the highest-impact changes you can make and takes two seconds to toggle.

# enable Reduce Motion via Terminal
defaults write com.apple.universalaccessReduceMotion -bool true

Log out and back in (or restart) for this to take full effect.