The short answer
photolibraryd is part of macOS. It manages the Photos library on your Mac and syncs it with iCloud Photos, for Photos and for any other app that reads your photos. It gets busy when you import a lot of photos, turn on iCloud Photos, open a library for the first time after a macOS update, or restore a library from a backup. Apple says the time an iCloud Photos upload takes depends on the size of your collection and your internet speed. Let it finish with the Mac plugged in and online. Quitting it only pauses the work, because macOS starts it again.
On this page
What photolibraryd does
photolibraryd is a system process. It runs from /System/Library/PrivateFrameworks/PhotoLibraryServices.framework and starts by itself whenever something needs your photo library, whether that's Photos or another app showing the photo picker.
| Process | What it does |
|---|---|
photolibraryd | Manages the library itself: imports, edits, albums, and syncing with iCloud Photos. |
cloudphotod | Moves photos and videos to and from iCloud for photolibraryd. |
photoanalysisd | Recognises people and pets and builds Memories. See photoanalysisd. |
mediaanalysisd | Reads photos and videos for text, objects and scenes. See mediaanalysisd. |
photolibraryd- What it does
- Manages the library itself: imports, edits, albums, and syncing with iCloud Photos.
cloudphotod- What it does
- Moves photos and videos to and from iCloud for photolibraryd.
photoanalysisd- What it does
- Recognises people and pets and builds Memories. See photoanalysisd.
mediaanalysisd- What it does
- Reads photos and videos for text, objects and scenes. See mediaanalysisd.
Why photolibraryd is using CPU or memory
It works when the library changes. The long busy spells usually follow one of these:
- Turning on iCloud Photos. The whole library is compared with iCloud, then uploaded or downloaded.
- A large import, from a camera, an iPhone or a folder.
- A macOS update. Photos updates the library the first time you open it afterwards.
- A new Mac or a restored library. Everything is checked against iCloud again.
- Lots of edits or deletions at once, which have to be saved and synced to your other devices.
During a sync you'll often see network activity as well as CPU, because photos and videos are being uploaded or downloaded. Once the library and iCloud match, photolibraryd goes back to using almost nothing.
How to check what it's doing
- Open Photos, select Library in the sidebar and look at the status line under your photos. It says whether Photos is updating, uploading or downloading, and how many items are left.
- In Activity Monitor, type “photo” in the search field to see the Photos processes together. The Network tab shows whether one of them is sending or receiving data.
top -l 2 -o cpu -n 40 -stats pid,command,cpu,mem | grep -E "photolibraryd|cloudphotod|photoanalysisd|mediaanalysisd"Is it safe to quit photolibraryd?
It quits and restarts itself. Quitting it in Activity Monitor doesn't damage the library, but macOS starts it again as soon as something needs your photos, and the sync continues from where it stopped. Don't force quit it while Photos is importing: let the import finish first.
What to do about it
- Leave the Mac awake, plugged in and connected to the internet, and let the sync finish. A big library can take a long time on a slow connection.
- If you need the Mac to be quiet now, pause the upload. Apple says you can pause iCloud Photos uploads for one day from the Library view in Photos, and that Pause isn't available in every library state.
- If the status line hasn't changed for a day, quit Photos, restart the Mac and open Photos again.
- If it still never settles, run Apple's Repair Library tool. Back up the library first, then hold Command and Option while you open Photos. With iCloud Photos on, the library syncs again afterwards, so expect another busy spell.
The faster way: “What is this?” in iKnowMyMac
iKnowMyMac groups the Photos background processes under Photos, adds up their CPU and memory, and explains in one line what they're doing, whether they're safe to quit, and what helps.