The short answer
mediaanalysisd is part of macOS. It analyses the photos and videos in your library for text (Live Text), objects, scenes and Visual Look Up, so Photos and Spotlight can search them. It gets busy after you import a lot of photos, turn on iCloud Photos, move to a new Mac or install a macOS update with new analysis models, and it mostly waits until the Mac is idle. High CPU for a few hours or days after one of those is normal. Let it finish: keep the Mac plugged in and idle with Photos closed. Quitting it only pauses the work, because macOS starts it again.
On this page
What mediaanalysisd does
mediaanalysisd belongs to the MediaAnalysis part of macOS. It reads each photo and video once and stores what it found, so later searches are instant. It's a system process and runs from /System/Library/PrivateFrameworks.
| Feature | What mediaanalysisd works out |
|---|---|
| Search in Photos and Spotlight | Objects and scenes, so a search for “beach” or “dog” finds the right photos. |
| Live Text | Text inside photos and video frames, so you can select and copy it. |
| Visual Look Up | Plants, animals, landmarks and artwork it can tell you more about. |
| Memories and suggestions | Shared with photoanalysisd, which handles people and pets. |
Search in Photos and Spotlight
- What mediaanalysisd works out
- Objects and scenes, so a search for “beach” or “dog” finds the right photos.
Live Text
- What mediaanalysisd works out
- Text inside photos and video frames, so you can select and copy it.
Visual Look Up
- What mediaanalysisd works out
- Plants, animals, landmarks and artwork it can tell you more about.
Memories and suggestions
- What mediaanalysisd works out
- Shared with photoanalysisd, which handles people and pets.
Why mediaanalysisd is using so much CPU
It works through everything that hasn't been analysed yet, so busy spells follow anything that adds a lot of new work:
- Importing a lot of photos or videos at once.
- Turning on iCloud Photos, when the library downloads to this Mac.
- Setting up a new Mac or restoring a library from a backup.
- A macOS update that brings new analysis models, so the whole library is read again.
Apple says this kind of Photos analysis happens while you aren't using the app and can take up to a few days on a large library. A Mac that's rarely left idle takes longer to get through it.
How to check it
top -l 2 -o cpu -n 30 -stats pid,command,cpu,time | grep -E "mediaanalysisd|photoanalysisd|photolibraryd"In Activity Monitor, open the CPU tab and type “analysis” in the search field. The % CPU column is how busy it is now and CPU Time is how long it has worked in total. A large CPU Time that stops growing means it has finished.
Is it safe to quit mediaanalysisd?
Yes, but it doesn't help. Quitting it from Activity Monitor breaks nothing, and macOS starts it again the next time there's work to do. The library still has to be analysed, so quitting only makes it take longer.
How to get it to finish
- Close Photos and leave the Mac idle and plugged in for a few hours. Analysis waits while you use the Mac, and runs much faster when it's idle.
- Give a large library a few nights. Leaving the Mac awake and plugged in overnight is often enough.
- If it stays busy for days with no new photos, restart once and leave it idle for an hour.
- If it still never settles, the library may be damaged. Back it up, then hold Command and Option while you open Photos to run the Repair Library tool.
The faster way: “What is this?” in iKnowMyMac
iKnowMyMac groups the Photos background processes under Photos, adds up their CPU, and explains in one line what they're doing, whether they're safe to quit, and what helps.