What is mds on Mac?
By Junaid, maker of Taskglass · Last reviewed
The Spotlight metadata server: coordinates indexing so you can search your Mac instantly.
mds is the metadata server behind Spotlight. It coordinates indexing of your files, hands work to mdworker processes that read the files, and answers searches from Spotlight, Finder and other apps. Heavy activity is normal after a macOS update, after restoring or migrating files, or when you connect a new drive, and it settles once indexing is done.
- Category
- Apple service
- Made by
- Apple
- Safe to quit:
- With care
Shown in Activity Monitor as mds
Why is mds using so much CPU or memory?
- Indexing after a macOS update, migration or restore
- A new external drive connected, or large numbers of files added or changed
- Cloud folders or developer folders with many files changing constantly
- A damaged index being rebuilt
What to do
- 1Let it finish: keep the Mac on and plugged in; indexing can take hours on large disks
- 2Exclude folders you never search (build folders, VM images, backups) in System Settings > Spotlight > Search Privacy
- 3If it runs for days, rebuild the index: add your disk to Search Privacy, then remove it again
- 4Restart your Mac
Safe to quit? With care.
macOS relaunches it right away; search may be incomplete while indexing continues.
Typical usage
Rough ranges on Apple Silicon Macs. Yours will vary.
- CPU
- Near 0% when idle; 10–100%+ while indexing
- Memory
- 20–200 MB
Related processes
- mds_storesMaintains Spotlight's search index on disk, updating it as files change.
- mdworkerA Spotlight worker that reads files and extracts searchable details for the index.
- mdworker_sharedSpotlight indexing worker; modern macOS runs several at once to read files for search.
- SpotlightThe Spotlight search window and menu bar search you open with Command-Space.
- corespotlightdIndexes content that apps share with Spotlight, like emails, notes and messages.
Part of the Taskglass Process Library