iCloud & iCloud Photos · iCloud Photos and the Photos library
Does iCloud Photos keep my photos and videos at full quality?
Short answer: Yes — iCloud keeps your originals at full quality, RAW included. With Optimize Mac Storage your Mac holds smaller versions and fetches the original when you open or export a photo. Shared Albums are the exception: they use reduced copies.
Yes. iCloud Photos stores your original photos and videos at full quality in iCloud, including formats like RAW. What changes is only what each device keeps: with Optimize Mac Storage, the Mac holds smaller versions and downloads the original when you open or export it.
So a blurry-looking photo on an optimized Mac usually just hasn't downloaded its original yet — see why photos look low resolution. Shared Albums are the exception: they use reduced copies.