photoanalysisd High CPU Process on macOS — Safe Mac Fixing Guide

Short info on photoanalysisd: The Photos app’s image analysis daemon. It scans your Photos library to perform face recognition, object recognition, scene classification, and gather metadata for features like Memories and search. It runs in the background (especially on AC power) so Photos can group faces and make your images searchable by content.

Typical High-Usage Symptoms: When active, photoanalysisd can be very resource-intensive—often 50–300% CPU (on multi-core Macs) for long periods. Users notice heat/fans after large imports or OS upgrades (which can trigger re-analysis). In Activity Monitor, it sits at the top of the CPU column; memory usage can also be significant for large libraries. Photos may show “Updating” while the daemon works. Very large libraries can take days or weeks of intermittent analysis (it pauses on battery by design).

Common User Complaints: Many users report their Mac slows to a crawl with photoanalysisd “eating CPU.” This is especially visible after setting up a new Mac or enabling iCloud Photos. For massive libraries (hundreds of GBs), the process can consume hours of CPU time and appear to never finish. Force-quitting stops analysis features (e.g., People album), which leads to frustration.

Affected Versions/Hardware: Seen across macOS releases since Sierra. Intel dual-core systems struggle the most; Apple Silicon (M1/M2/M3) completes work much faster but still runs CPUs hard while active. Any Mac with a sizable Photos library—especially after OS updates or initial iCloud sync—can trigger this behavior.

1. Introduction

photoanalysisd powers Photos features like People, Memories, and content search. After big imports, first iCloud Photos syncs, or OS upgrades, it can peg the CPU for long stretches. This guide shows you how to confirm it’s the real culprit, decide whether to let it finish vs throttle/pause, fix stalls, and keep performance acceptable without breaking Photos.

2. Quick Triage (5–10 minutes)

1. Verify the culprit. Open Activity Monitor → CPU, sort by % CPU. If photoanalysisd is on top after recent imports/upgrade/iCloud enablement, this is expected background work.
2. Check Photos status. Open Photos and look for banners like “Updating…” or progress in People. If progress moves (even slowly), the safest fix is to let it finish.
3. Free headroom. Ensure ≥ 10–20% free disk space; close heavy apps to reduce contention.
4. Choose a path: Want it done ASAP? Run it overnight on AC power. Need responsiveness now? Throttle/pause. Suspect it’s stuck? Use the repair/reset steps below.

3. Prerequisites

• Admin account (for a few steps).
• Mac connected to power and reliable network (for iCloud Photos users).
• Optional: Terminal familiarity for monitoring and tuning.

4. Step-by-Step Guide

4.1. Let it finish (fastest overall, least risky)

1. Plug in power and ensure stable network if using iCloud Photos.
2. Keep the Mac awake so analysis can run continuously:

   caffeinate -diu
   

   Leave the Terminal window open while you’re away (-d display, -i system idle, -u user activity).

3. Quit heavyweight apps (video editors, VMs, excessive browser tabs).
4. Leave Photos closed. photoanalysisd runs headless; Photos doesn’t need to be open.
5. Overnight check: CPU should drop and Photos should report reduced or no pending analysis.

4.2. Make the Mac responsive now (throttle without breaking features)

1. Lower photoanalysisd priority instead of killing it:

   PID=$(pgrep -x photoanalysisd) && sudo renice +20 -p "$PID"
   

   This yields CPU to interactive apps without disabling analysis.

2. Pause People scanning (if offered): Photos → People → click Pause while it says “Updating People…”.
3. On laptops: Temporarily run on battery; analysis is far less aggressive off AC power.
4. Schedule windows: Use caffeinate only overnight; stop with Ctrl+C when you return.

4.3. Pause/Defer iCloud-related churn (if that’s the trigger)

1. Pause iCloud Photos (temporary): Photos → Settings → iCloud shows Pause during active syncing.
2. Stage imports: Import in batches (by year/album) and allow overnight processing between batches.

4.4. Fix “stuck” or looping analysis

If CPU stays high for days with little/no progress or Photos shows errors:

1. Basic reset via safe quit
   • Quit Photos.
   • In Terminal:

     killall photoanalysisd
     

     (It will relaunch automatically.)

   • Reopen Photos and check status.
2. Repair the Photos library (Apple-supported)
   • Quit Photos.
   • Hold Option+Command and open Photos to invoke Repair Library.
   • Let repair complete (can take hours; it re-verifies items).
3. Test with a new library (isolation)
   • Quit Photos → hold Option while opening Photos → Create New… (import a small album).
   • If behavior is normal here, your main library needs repair or splitting.
4. Check filesystem/space
   • Ensure ≥ 15–20% free disk space.
   • Run Disk Utility First Aid on the startup disk.
   • If library is on external storage, use a fast SSD formatted APFS or HFS+ (avoid exFAT/FAT) and connect via USB-C/Thunderbolt.
5. Reset background state (last resort before restore)
   • Disable iCloud Photos in Photos → Settings → iCloud (confirm originals/backups).
   • Reboot, then re-enable iCloud Photos and allow a full re-index.

Avoid: deleting internal Photos/Face databases by hand. Schemas change between macOS releases; manual removal can corrupt or permanently lose People/metadata.

4.5. Enterprise/Admin levers (optional)

1. CPU friendliness on shared workstations: Use renice via a LaunchAgent that watches for new photoanalysisd PIDs and auto-renices them.
2. User education & staging: Stage initial ingestion after-hours with caffeinate on AC power.
3. Storage policy: Keep Photos libraries on fast local SSD. Avoid network shares for active libraries.

5. Validation and Testing

1. Activity Monitor: photoanalysisd drops from sustained triple-digit CPU to brief spikes or idle when finished.
2. Photos UI: Banners disappear; People populates; content searches (e.g., “dog”, “beach”, “car”) work.
3. Terminal checks:CPU snapshot:

   ps -o pid,pcpu,etime,command -p $(pgrep -x photoanalysisd)
   

   Recent logs (optional):

   log show --style compact --last 2h --predicate 'process == "photoanalysisd"'
   

6. Security Considerations & Hardening

1. Verify it’s Apple-signed:

   PID=$(pgrep -x photoanalysisd)
   PLIST=$(ps -p "$PID" -o comm=)
   codesign -dv --verbose=4 "$PLIST"
   

   Expect Apple authorities and a valid Apple Team ID.

2. Privacy note: Analysis is on-device. If you don’t want face/object recognition on certain media, use a separate user account or a dedicated Photos library you only open when needed.
3. Avoid “optimizer” apps or kernel extensions promising CPU limits; they often degrade stability/security.

7. Expected Impact and Trade-offs

• Letting it finish yields the best long-term performance; future imports analyze incrementally.
• Throttling/pausing keeps the Mac responsive but extends total wall-clock time to completion.
• Repairing the library fixes stalls but may trigger re-verification and a fresh analysis pass.

8. Conclusion

High CPU from photoanalysisd is normal after big Photos library changes. The most reliable strategy is to run on AC power, prevent sleep with caffeinate, and let it finish. When you need immediate responsiveness, lower its priority or pause scanning, then resume overnight. If analysis appears stuck, repair the Photos library, verify disk health, and re-index if necessary. Avoid manual database edits.

9. References / Built-in Tools

• Activity Monitor, Photos Repair Library (hold Option+Command on launch), Terminal (caffeinate, renice, log), Disk Utility.
• Apple Support articles: search for “Photos library repair”, “People album”, and “If Photos is using significant CPU” for your macOS version.

10. FAQ