Use Photos on iCloud.com on your iPhone
With Photos on iCloud.com, you can access photos and videos stored in iCloud Photos from anywhere.
Note: To view shared albums or photos stored in My Photo Stream, use the Photos app on your iPhone. See Use iCloud with Photos on your iPhone, iPad or iPod touch.
What can you do in Photos on iCloud.com on your iPhone?
View photos and videos: View photos and videos stored on any device with iCloud Photos turned on.
Upload and download: Upload photos from your device to iCloud Photos. Download photos and videos from iCloud.com to your device. See Upload and download photos using iCloud.com.
If you’re using another feature on iCloud.com, you can switch to Photos by tapping the feature’s name in the top-left corner of the iCloud.com window.
Web-only accounts are not supported on iCloud.com on a phone. To use Photos and other features on iCloud.com, set up iCloud on your iPhone, iPad, iPod touch, Mac or Windows computer. To learn more about web-only access, see the Apple Support article Web-only access to iCloud.