What is photoanalysisd on Mac?
photoanalysisd is the Photos app’s background brain: it finds faces, groups people and pets, builds Memories and picks featured photos. After importing a large library it can run for days, but only when your Mac is otherwise idle.
Updated
- Process
photoanalysisd- Comes from
- macOS
- Safe?
- Safe. Part of Photos; quitting it only pauses the work, and it will start again later.
What photoanalysisd does
photoanalysisd lives at /System/Library/PrivateFrameworks/PhotoAnalysis.framework/Versions/A/Support/photoanalysisd and runs as your user. It builds the parts of Photos that feel “smart”:
- the People & Pets album (face detection, then clustering faces into people)
- Memories, featured photos and the For You suggestions
- the photo knowledge graph: trips, holidays, home and work locations, events
It works together with mediaanalysisd, which handles lower-level image and video recognition. Both are scheduled by macOS as background work, so they prefer moments when you aren’t typing or clicking and the Mac is on power.
Why it uses CPU, memory and energy
- A new or migrated library: setting up a new Mac or turning on iCloud Photos means every photo is new to this Mac.
- A big import: hundreds of photos from a camera or phone at once.
- A macOS upgrade: new versions often bring updated models, and the library gets reanalyzed.
- Your Mac is never idle: if it only runs at night but the Mac sleeps, it never finishes and keeps restarting each day.
On a MacBook it can noticeably warm the machine and drain the battery during its first big run.
How to make it finish (or stay quiet)
The quickest way through is to let it run: plug in the Mac, open Photos, then leave it. Keep the Mac awake for a few hours with:
caffeinate -i -t 14400
That holds off idle sleep for four hours (see how to keep your Mac awake). You can check whether it’s still busy with:
top -l 1 -stats pid,command,cpu,mem | grep -i photoanalysis
If you need the CPU right now, quitting it in Activity Monitor is harmless; macOS will start it again later. If you don’t use Photos at all, there’s nothing to analyze and it stays idle. Libraries in other apps (Lightroom, a folder in Finder) are not touched by photoanalysisd.
A library that keeps getting reanalyzed may be damaged. Hold ⌥ Option and ⌘ Command while opening Photos to run the Library Repair tool (back up first).
When to worry
Check that it is Apple’s binary running as you:
ps -o user,pid,command -p $(pgrep -x photoanalysisd)
The path should be inside PhotoAnalysis.framework. If photoanalysisd runs at full CPU for weeks with no change in the People album, or Photos shows a library error, it’s stuck rather than slow; repairing the library usually ends it.
Seeing it in Stat Space
Stat Space’s Apps tab shows CPU and memory per app, and with Pro, battery drain since unplug tells you what share of a charge went to Photos’ background work. Stat Space’s keep-awake timer (in the Awake tab) does the same job as caffeinate, if you’d rather not leave a Terminal window open overnight.
Questions
Can I turn off photoanalysisd?
Not permanently without disabling system protection, which isn’t worth it. It only runs for libraries that Photos manages, and it slows down or pauses while you’re actively using the Mac.
How long does photoanalysisd take?
Roughly an hour per few thousand photos on Apple Silicon, though it only works in idle time. A 50,000-photo library synced from iCloud can take several days of on-and-off work.
Does photoanalysisd upload my photos?
No. Face and scene analysis happens on your Mac. Results such as people names sync between your devices through iCloud if iCloud Photos is on.
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