Short answer: yes and no, and the honest version depends on one setting. With iCloud Photos on, your full-resolution originals live in iCloud and the phone holds either a full copy (Download and Keep Originals) or a size-managed subset (Optimize iPhone Storage). The part worth slowing down for is the other direction: turning iCloud Photos off presents a dialog whose two options have very different consequences, and one of them removes photos from the phone.
Does iCloud Photos take up space on the phone?
It depends on which of the two settings is active. The switch lives at Settings → your name → iCloud → Photos.
- Optimize iPhone Storage — the phone keeps device-sized versions and downloads the full-resolution original when you open, edit, or share an item. How much it keeps is decided by iOS, not by you.
- Download and Keep Originals — every full-resolution file stays on the phone as well as in iCloud. Choose this deliberately, for example before travelling somewhere without reliable data.
The key point that people miss: iCloud Photos does not move your library off the phone automatically. It makes originals *eligible* to be replaced by previews. Eligibility is not the same as action.
For what is actually inside the "Photos" block in Settings → General → iPhone Storage — Recently Deleted, Messages attachments, Live Photos, cache — see iPhone Photos Taking Up Storage. This page is about the switch itself and what changing it does.
Why "Optimize" frees less than you expect
Three reasons, and understanding them stops the "it doesn't work" conclusion:
It is demand-driven, not scheduled. iOS evicts full-resolution originals when it needs space, and it does not bother on a phone with plenty of free room. A half-empty device will show almost no change; a nearly full one will show a real change within days.
Recent items stay local. Whatever you shot or opened recently is kept at full resolution, because downloading it back every time would be miserable. If most of your library is recent, there is little to evict.
It only works after the upload finishes. Until the library is fully in iCloud, there is no safe original to remove. A large library on a slow connection can take days. This is also where the danger lives, and it is the reason for the order in the next section.
⚠️ Turning iCloud Photos off: what the two options actually mean
Tap the switch off and iOS asks a question. The two answers are not variations of the same thing:
| Option | What it does | Risk |
|---|---|---|
| Download Photos & Videos | Downloads full-resolution copies to the phone first, then stops syncing | Needs enough free space; if there is not, the download can fail and leave a partial library |
| Remove from iPhone | Removes the local copies, keeping the library in iCloud | Any item not yet uploaded is gone permanently |
The dialog describes neither consequence clearly. The rule that matters:
Before either option, confirm the upload is complete. Open Photos, go to the Library tab, scroll to the bottom, and look for a sync status or a pending-items count. If it is still uploading, stop — turning the switch now puts everything not yet uploaded at risk, and "Remove from iPhone" will delete it.
A related trap: with iCloud Photos off, your camera roll becomes part of your iCloud backup, which usually makes the backup much larger. With it on, photos are not in the backup at all — they are in iCloud. That switch flips the meaning of your backup, which is worth knowing before you rely on either. See iCloud vs Computer Backup.
How to turn it off safely
In order, and do not skip the first step:
- Confirm the upload finished. Library tab, scroll to the bottom, no pending count.
- Check free space against the size of your library, if you plan to keep originals locally.
- Choose "Download Photos & Videos" if you want the photos to stay on the phone, then wait for it to finish before doing anything else.
- Only then consider "Remove from iPhone" — and only when you are certain the library is complete in iCloud.
- Verify on another device (iCloud.com or an iPad) that the items you care about are visible there.
If the phone is nearly full and you want to stay in iCloud rather than leave it, you do not need to turn anything off — turning on Optimize iPhone Storage, plugging in, and leaving it on Wi-Fi overnight is the slower but non-destructive path. For what to clear first if space is critical, see Why Your iPhone Storage Is Full.
Shared Albums versus Shared Library
Two features with similar names and opposite storage behaviour:
- Shared Albums (
Settings → Photos → Shared Albums) — items live in iCloud and are streamed. Local cost is thumbnails. Removing an album unsubscribes you; the owner's copy is untouched and nothing of yours is freed. - iCloud Shared Library — another person's photos are merged into your main library. These behave exactly like your own items: they count in the storage screen and they are part of Optimize's decisions.
If you are trying to free space, know which one you are looking at. Removing a Shared Album frees almost nothing, which is why "I deleted the album and nothing changed" is a common report.