macOS update is stuck or very slow to install

Why it happens

Installing macOS takes a lot of work behind the scenes, and the progress bar isn't a good clock. It can sit still for a long time, jump ahead, or the screen can go black and the Mac restart a few times. Real stalls usually come from too little free storage, a flat battery or a dropped download.

How to fix it

1. Plug in the charger and leave the Mac alone. Don't close the lid on a laptop.

2. Give it time. The bar can sit on one spot for an hour or more during a big upgrade, and a few restarts or a black screen along the way are part of it. Overnight is the safest test.

3. If the bar truly hasn't moved for several hours, press and hold the power button (Touch ID on a MacBook) for up to 10 seconds until the Mac turns off. Wait a few seconds, then press it again to turn it on.

4. Once you're back at your desktop, open the Apple menu, choose System Settings, click General, then Software Update. Let it check, and install the update again.

   General›Software Update

Still not fixed?

1. Check your free space in General > Storage. A major upgrade needs many gigabytes free. Delete large files and empty the Trash, restart, then try again.

   General›Storage

2. If the download is stuck on estimating time, check your Wi-Fi works, restart, and try again later. Apple's servers can be busy on release day.

3. Unplug accessories like hubs, drives and docks, then try again. Start in Safe Mode and run Software Update from there if it keeps failing.

4. If the Mac now sticks on the Apple logo every time it starts, start up in macOS Recovery and choose Reinstall macOS. Your files stay, but back up first if you can.

5. If Recovery won't open or reinstalling fails too, contact Apple Support. A Mac with Apple silicon can sometimes be revived with a second Mac, and they can help with that.