You snap a photo on your iPhone, open the Photos app on your Mac, and it's simply not there. Or the Mac sits for days on “Updating iCloud Photos…” with a progress bar that never fills. When iCloud Photos stops syncing, your library quietly splits in two — and you notice at the worst moment, hunting for a picture that's on the other device.
The good news: this is almost always a settings, storage, or account hiccup — not a broken Mac or lost photos. Work through the fixes below in order. The first three take about two minutes and clear the large majority of cases.
The 30-second fixes (try these first)
Before anything drastic, rule out the simple stuff. These clear up most sync stalls on their own:
- Plug in and connect to Wi-Fi. iCloud Photos deliberately pauses uploading and downloading when your Mac is on battery or on a metered/cellular connection. Plug into power, join a real Wi-Fi network, and open Photos — syncing often resumes on its own within a minute.
- Scroll to the bottom of the Library. In the Photos app, click Library in the sidebar and scroll all the way down. macOS shows the sync status there — “Updating,” “Paused,” or a “Resume” link. If it says Paused, click Resume.
- Confirm the same Apple Account on both devices. On the Mac: System Settings → [your name] at the top. On the iPhone: Settings → [your name]. If the emails don't match, the two devices are syncing to different iClouds — which alone explains “my photos aren't there.”
Still out of sync? Keep going.
Step 1: Make sure iCloud Photos is actually turned on
This is the toggle most people never check. iCloud can be signed in while Photos specifically is switched off — so nothing uploads or downloads.
- Open System Settings and click your name at the top.
- Click iCloud, then Photos.
- Make sure Sync this Mac is On.
If it was already on, toggle it off, wait ten seconds, then back on. That single off/on cycle forces a fresh handshake with iCloud and revives a surprising number of “it just stopped” cases. Do the same on your iPhone under Settings → [your name] → iCloud → Photos.
Step 2: Understand “Optimize Mac Storage” before you panic
If photos appear on your Mac but show a small cloud icon or download slowly when you open them, sync isn't broken — Optimize Mac Storage is working as designed. With that setting on, full-resolution originals live in iCloud and the Mac keeps lightweight previews until you open a photo.
You'll find the choice under System Settings → [your name] → iCloud → Photos:
- Optimize Mac Storage — keeps originals in iCloud, saves disk space. Photos download on demand.
- Download Originals to this Mac — keeps every full-resolution photo locally. Pick this if you want everything available offline (and have the disk space for it).
Switching to Download Originals will pull your whole library down — which needs both time and free space, the subject of the next step.
Step 3: Check free disk space and iCloud storage
Two storage limits stall sync in opposite directions:
- A nearly full Mac. If your startup disk has almost no room, macOS can't download originals or stage new imports. Check System Settings → General → Storage. Aim to keep at least 10–20 GB free.
- Full iCloud storage. If your iCloud is maxed out, new photos have nowhere to upload — the Mac shows “Updating” forever while the iPhone quietly stops backing up. See our guide on what to do when iCloud storage is full to free room or right-size your plan.
Step 4: Restart, and let it finish on power overnight
A stuck “Updating iCloud Photos” bar is often just a large library that keeps getting interrupted. Give it an uninterrupted run:
- Restart the Mac. Not sleep — a real Apple menu → Restart. This clears a stalled sync process on its own more often than you'd expect.
- Plug into power, join Wi-Fi, and leave the Mac awake and open overnight. A first-time sync of thousands of photos can genuinely take hours; it only makes progress while the Mac is on power and not asleep.
- To keep it from sleeping, set System Settings → Displays → Advanced to prevent sleep while on power, or nudge the mouse periodically.
Come back the next morning and re-check the status line at the bottom of the Library.
Step 5: Check Apple's system status
Occasionally the problem isn't yours at all. Search “Apple System Status” and confirm Photos and iCloud both show a green dot. If Apple is having an outage, there's nothing to fix on your end — syncing resumes once their status page goes green again.
Step 6: When a specific photo won't sync
If most of your library syncs but one or two items never appear, the culprit is usually a single unsupported or damaged file:
- Unsupported formats (some RAW files, screen recordings, or third-party edits) can hang the queue. Try exporting that item to a standard JPEG or HEIC and re-importing it.
- Videos take far longer than stills — a few 4K clips can make the whole library look “stuck” while they upload. Give videos extra time before assuming a failure.
If the Photos app itself freezes mid-import rather than mid-sync, that's a different problem — see our guide on the Photos app stuck importing.
If it's still not syncing: rebuild the account
A stubborn library that survives every step above usually has a corrupted local sync token. The clean fix is to sign the iCloud account out and back in:
- Confirm your photos are safe first — sign in at iCloud.com from any browser and open Photos there. If they're on the web, your originals are safe on Apple's servers.
- On the Mac, go to System Settings → [your name], scroll to the bottom, and Sign Out of iCloud (choose to keep a copy of your data).
- Restart, then Sign back in and re-enable Photos.
This forces the Mac to rebuild its photo database from Apple's clean server copy — the reset that finally clears the most persistent cases.
When it's not iCloud — it's the Mac
If you're on an older macOS version, sync services can misbehave in ways no toggle fixes. Confirm you're current — see how to update macOS. And if the same Mac is dropping other iCloud services (Calendar drifts, Messages won't come through), the pattern points at the account or the machine rather than Photos specifically — our guides on Calendar not syncing and iMessage not working on a Mac cover the neighboring symptoms. A Mac too old to run a current macOS is often the real bottleneck — and an affordable Mac that handles a big photo library can end the fight for good.
Frequently asked questions
Why are my iPhone photos not showing up on my Mac?
The two most common causes are (1) the devices are signed into different Apple Accounts, or (2) iCloud Photos is toggled off on one of them. Confirm the same account on both, then check that Sync this Mac is on under iCloud → Photos, and that iCloud Photos is on in the iPhone's Photos settings.
How do I force iCloud Photos to sync on my Mac?
Plug into power, join Wi-Fi, open Photos, and scroll to the bottom of the Library — if it says Paused, click Resume. iCloud Photos has no manual “sync now” button, so removing the pause conditions (battery, poor network, sleep) is how you push it.
Why is my Mac stuck on “Updating iCloud Photos”?
Usually it's a large library still uploading or downloading, repeatedly interrupted by sleep or a dropped connection. Keep the Mac awake on power and Wi-Fi overnight. If it hasn't moved in a full day, restart and sign out and back into iCloud to rebuild the sync.
Will turning off iCloud Photos delete my photos?
No — when you turn it off, macOS asks whether to download a copy to the Mac first. Choose to keep them. Your originals also remain safe on Apple's servers and at iCloud.com regardless.
Still fighting a Mac that won't cooperate — slow, low on space, or stuck on an old macOS it can't update? Sometimes the machine, not the settings, is the problem. Browse all our Mac guides for the next thing to try.