iCloud & iCloud Photos · iCloud Photos and the Photos library
Why are my photos not syncing to iCloud from my Mac?
Short answer: Check the status line at the bottom of the Photos library. Common causes are full iCloud storage, paused syncing, iCloud Photos switched off, the library not being the System Photo Library, or a slow connection.
Check the status at the bottom of the Photos library view — it says whether syncing is up to date, paused or waiting, and why. The usual causes:
- iCloud storage is full — uploads stop until you free space.
- Syncing is paused — Photos can pause itself (for example to save power), or you paused it; click Resume.
- This library isn't the System Photo Library — only that one syncs.
- iCloud Photos is off in Photos → Settings → iCloud.
- Signed out, or a slow or interrupted connection.
Large libraries simply take a long time the first time. See how long the first upload takes.