Why is mediaanalysisd using so much CPU on my Mac?

What mediaanalysisd is

Apple says very little about mediaanalysisd itself. There’s no manual page for it (man mediaanalysisd finds nothing on macOS 27), and Apple’s support pages describe the features it serves, not the process. Here’s what each side says.

Apple, on the features: Live Text lets you copy and use the text in a photo, like a roadside sign, and Control-click it to look it up, translate it or search the web for it. Visual Look Up helps you learn about popular landmarks, art, plants, flowers, pets and other objects in your photos: open a photo in Photos and click the Visual Look Up button in the toolbar.

The Eclectic Light Company, on the process: it has traced these features through macOS’s logs and reports that mediaanalysisd is one of their central parts. When an image opens, macOS runs Live Text first so you can select the text quickly, then analyzes parts of the image for Visual Look Up, and on Apple silicon it uses the Neural Engine heavily for this. It also reports that mediaanalysisd extracts text from images and PDFs so Spotlight can find them, and that this work is computationally intensive and can take a long time. These process details are theirs, not Apple’s.

When it runs, and why it’s busy now

Because the text it finds goes into Spotlight’s index, mediaanalysisd tends to be busy when Spotlight is. Apple says Spotlight indexes when you first set up a Mac, after software updates and upgrades, and as your data changes, and that a full index can take hours or even days depending on how much data there is. So the busy times are:

• The first hours or days after a macOS update or upgrade.
• A new Mac, or files moved over with Migration Assistant.
• A big batch of new images, screenshots or scanned PDFs, from a camera, a download or iCloud.

The Eclectic Light Company says this kind of analysis is normally put off until it disturbs you least. In its macOS 27 tests, mediaanalysisd ran at a low background priority, which normally keeps it on the efficiency cores of an Apple silicon Mac. Photos does its own library analysis too, as photoanalysisd; see Why is photoanalysisd using so much CPU?

The one-minute check

1. Open Activity Monitor (it’s in Applications, Utilities), click CPU and type analysis in the search field to see mediaanalysisd and photoanalysisd together.
2. Press Command-Space. Apple says that while Spotlight is indexing, a progress indicator shows at the top of the Spotlight window. If it’s there, the Mac is still catching up, and mediaanalysisd is part of that.
3. Watch it for a few minutes. CPU from mediaanalysisd with nothing else busy is analysis at work, not a fault.

% CPU counts each core as 100%, so it can read over 100% on a Mac with several cores.

What to do

Let it finish

Leave the Mac plugged in, awake and online, overnight if you’ve just updated or moved a lot of images over. Apple says Spotlight indexing finishes sooner when the Mac is idle, plugged in and connected to Wi-Fi or Ethernet. Apple gives no time for image analysis itself; it depends on how many images there are.

If it never seems to finish

Restart, install any further updates in System Settings, General, Software Update, and give it another night on power. If Spotlight’s progress indicator never goes away either, the fixes in Why are mds_stores and mdworker using so much CPU? apply, including keeping folders you never search out of the index.

If the Mac gets hot

Hours of analysis can warm a MacBook and spin up the fans, and a fanless MacBook Air slows down instead. If it gets hot enough, macOS holds the busy processes back and kernel_task rises in the CPU list. See What is kernel_task? and Why is my Mac so hot?

What not to do

• Don’t force quit mediaanalysisd. It’s a macOS process, not an app you started. Quitting it doesn’t remove the backlog; the images still need reading next time it runs.
• Don’t exclude your whole internal disk from Spotlight to stop it. Apple warns that if you do, you won’t be notified about any updates.
• Don’t buy a “CPU fix” app. This is macOS doing work you’ll use: copyable text in photos, Visual Look Up and search.

Keep an eye on it from the menu bar

Activity Monitor names mediaanalysisd once you open it. Multimeter keeps the totals in the menu bar, so you can tell whether the Mac is still catching up without opening anything:

• CPU: total use across all cores, every 3 seconds on power and about every 6 on battery. The Sparkline face shows the last few minutes, so you can see the CPU climb while you’re away and settle when the backlog is done. Yellow above 70%, red above 90% by default.
• Thermal pressure: Nominal, Fair, Serious or Critical, the state macOS uses to decide when to hold performance back. It’s a state, not degrees.

Multimeter’s built-in meters show totals, not processes, so they won’t say the CPU is mediaanalysisd. If you want the name too, the Busiest process recipe is a Script meter that shows the top process name and its % CPU, and mediaanalysisd fits in full. Five live meters use about 3% CPU, and they pause while the displays sleep.