Download Apple updates once for every device at home
Quick answer
Turn on Content Caching in System Settings > General > Sharing on a Mac that stays on. Your other Apple devices then fetch updates from that Mac instead of the internet.
Why it happens
Each iPhone, iPad and Mac normally downloads its own copy of every update and app from Apple. On a slow or capped connection, five devices means five big downloads of the same thing. Content Caching lets one Mac keep a copy the first time, then hand it to the others over your home network. You don't set anything up on the other devices, because they find the cache by themselves.
How to fix it
Pick the Mac that's on most of the day, such as a desktop Mac or a MacBook that stays plugged in at a desk. A cable to the router works best, but Wi-Fi is fine too.
Open the Apple menu, choose System Settings, then click General and Sharing. Turn on Content Caching.
General›Sharing›Content Caching
If your Mac asks for your login password to confirm, type it in.
Keep that Mac switched on and connected. It uses some of its free storage for the saved copies and clears older ones when it needs room.
Next time one device downloads an update, the others on your network get the same update from this Mac, which is usually much faster.
Still not fixed?
Make sure every device is on the same home network as the Mac. A phone on mobile data, a guest network or a VPN can't see the cache and downloads from the internet as usual.
The cache only works while the Mac is awake. On a desktop Mac, turn on Prevent automatic sleeping when the display is off in Energy. On a MacBook, the matching switch is in Battery > Options… and works while it's plugged in.
Energy›Prevent automatic sleeping when the display is off
If the Content Caching switch is greyed out, this Mac may be managed by a school or company, and they can lock sharing settings. Ask whoever set it up.
Restart the Mac and turn Content Caching off and on again if it says it couldn't start.
If Content Caching still won't stay on after a restart and the latest macOS update, contact Apple Support.
Questions people ask
Do I need to set anything up on my iPhone or iPad?
No. iPhones, iPads and other Macs on the same network find the cache by themselves and use it automatically.
Does Content Caching use up my Mac's storage?
It uses some free space for the saved copies and removes older ones when the Mac needs room. You can turn it off at any time in General > Sharing.
Should I turn off Content Caching?
If you have only one or two Apple devices, or fast internet with no data limit, it makes little difference, so it's fine to leave it off.
Related fixes
Glad it worked.
Sorry it didn't. Tell us what happened and we'll fix this page.
Get there in one click with PinSet.
Press ⌃ ⌥ Space and type “family devices downloading same update”. PinSet opens General › Sharing in System Settings and rings Content Caching. One of 2,400+ checked Mac fixes. Works offline.
7 fixes free · Works offline · macOS 26 and 27