Save data on a hotspot or metered Wi-Fi with Low Data Mode

Why it happens

A Mac assumes Wi-Fi is unlimited, so it downloads updates, syncs photos and fetches app data whenever it likes. On a phone hotspot or a metered connection that can use gigabytes without you noticing. Low Data Mode tells your Mac and the apps that support it to pause that background work on this network only.

How to fix it

1. Connect to the hotspot or Wi-Fi network you want to limit. The setting is saved for each network separately.

2. Open System Settings and click Wi-Fi. Next to the network you're on, click Details….

   Wi-Fi›Details…

3. Turn on Low Data Mode and click OK. Your other networks, like home Wi-Fi, stay as they were.

4. When you're back on a normal connection, nothing needs undoing. The Mac only limits itself on the network where you turned it on.

Still not fixed?

1. A big macOS update can still start if automatic updates are set to download. To be sure, turn off Download new updates when available, and turn it back on later at home.

   General›Software Update›Automatic Updates›Download new updates when available

2. Some apps ignore Low Data Mode and keep streaming or syncing. Quit apps you aren't using with Command-Q, and pause big cloud uploads until you're on a faster connection.

3. If the Mac won't join the iPhone hotspot at all, check that Allow Others to Join is on in the iPhone's Personal Hotspot settings, then pick the iPhone from the Wi-Fi list on the Mac.

   Wi-Fi

4. Still using a lot of data? Open Activity Monitor, click the Network tab and see which app is sending or receiving the most, then quit it. If the Mac's Wi-Fi itself keeps misbehaving, contact Apple Support.