iCloud Photos — does Photo Transfer use the originals?
Yes. Even when your iPhone uses Optimize iPhone Storage and most of your photos exist as low-resolution previews on the device, Photo Transfer App pulls the full original from iCloud before sending.
How iCloud Photos changes things
If you've enabled iCloud Photos with the Optimize iPhone Storage option, most of your photo library on the device is just thumbnails or downscaled previews. The full-resolution originals live in iCloud. This saves space on your iPhone, but means a naive "read the photo and send it" would only transfer a low-res copy.
What Photo Transfer App does
When you pick a photo to send, Photo Transfer asks iOS for the full original. iOS responds by:
- Checking if the original is already on the device — if yes, returning it immediately.
- If not, downloading the original from iCloud (over your internet connection) before returning it.
The transfer itself still happens over local WiFi between your iPhone and the receiver — iCloud is only the source of the original file, never the path it travels.
What you'll notice
- The first few seconds of a transfer can feel slower than usual if iOS is fetching originals from iCloud.
- You'll see iCloud's loading spinner briefly on each thumbnail as the original downloads.
- Your iCloud storage isn't affected — Photo Transfer doesn't write anything back to iCloud.
If you don't want iCloud involved
Two options:
- Disable Optimize iPhone Storage: Settings → [your name] → iCloud → Photos → Download and Keep Originals. Your full library stays on the device. No iCloud round-trip during transfers.
- Disable iCloud Photos entirely: same path, toggle off iCloud Photos. Your iPhone keeps only what's already on-device.