coreduetd is a macOS daemon that learns how you use apps, contacts and devices for Siri Suggestions and similar features, and its launchd job serves Apple's knowledge, people and suggestion services; it's part of macOS. Busy spells after an update are normal, and if it stays busy for hours, restart the Mac and turn off the Siri Suggestions you don't use.
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One Mac, macOS 26.5 (25F71) on Apple silicon, read with ps and codesign on October 29, 2026
| Path | /usr/libexec/coreduetd |
|---|---|
| Runs as | root |
| Signed by | Apple (Software Signing), identifier com.apple.coreduetd |
| Note | Its launchd job, com.apple.coreduetd, starts it on demand rather than keeping it running. |
coreduetd is a macOS daemon that collects usage patterns to power proactive features such as Siri Suggestions. On macOS 26.5 its launchd job (com.apple.coreduetd) offers services named knowledge, people, and calendar and FaceTime interaction suggestions, and wakes when Siri Suggestions settings change. Apple says Siri Suggestions uses on-device processing to learn how you use your devices and apps, and syncs that personalization between your devices with end-to-end encryption if you use iCloud.
High CPU usage while processing accumulated interaction data after long uptimes
Elevated disk I/O as coreduetd writes usage patterns to its knowledge database
Increased activity after macOS updates when the knowledge model is being rebuilt
Privacy concerns about the scope of data being tracked locally on the device
In System Settings, open Siri (Apple Intelligence & Siri, or Siri & Spotlight, depending on your macOS version) and turn off the Siri Suggestions you don't use. That gives coreduetd less to do.
After a macOS update or a migration, coreduetd can stay busy for a while as it catches up. If the Mac is otherwise responsive, leave it plugged in and let it finish.
Run 'sudo killall coreduetd' in Terminal. launchd will automatically restart the daemon. This clears any stuck processing state and forces coreduetd to reinitialize, which resolves most high-CPU episodes caused by processing loops.
coreduetd running in the background with low resource usage is completely normal — it quietly learns your usage patterns. Be concerned if it sustains more than 25% CPU for more than 20 minutes, or if its memory usage climbs above 300 MB, which may indicate a corrupted knowledge database. Brief spikes during or after macOS updates are expected as it rebuilds its model.
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No. coreduetd is a legitimate Apple system daemon that powers Siri Suggestions, Handoff, and other intelligent features in macOS. It is code-signed by Apple and runs as part of the Core Duet framework. Apple says Siri Suggestions, which coreduetd serves, uses on-device processing.
Apple doesn't list what coreduetd itself stores. For Siri Suggestions, which coreduetd serves, Apple says it uses information on your device, such as Safari history, email, messages, contacts and what other apps share with it, processes it on the device, and syncs the personalization between your devices with end-to-end encryption if you use iCloud.
You cannot permanently disable coreduetd as it is a core system daemon managed by launchd. However, you can reduce its activity by turning off the Siri Suggestions you don't use. Its launchd job starts it on demand rather than keeping it running, so with less to do it runs less.
Under normal conditions, coreduetd has a negligible performance impact. It processes usage data opportunistically during idle periods. However, after a macOS update or if its database becomes corrupted, it may temporarily use significant CPU while rebuilding its knowledge model. This spike is temporary and resolves within a few hours.
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