Check Apple server. Like other cloud services, iCloud also stores your uploaded photos to Apple's. Reader Stephen Love writes in about uploading photos that are stored in Photos or iPhoto to websites. He knows he can navigate to a photos library—an OS X package that can be opened—and find.
6 Solutions - Fix iCloud Photo Library Not Uploading Photos Problem
Keep in mind that the upload speed relies heavily on your cable. Generally, photo upload is very slow on iCloud especially when a full library is uploaded. If there are iPhone videos to be uploaded to iCloud, it's going to take even longer. It will be quite normal to take hours for a large photo library. This is not an iCloud photos not uploading problem and you may just wait. If you find the iCloud Photo Library stuck uploading from Mac on iPhone XS/SR/X/8/7/6S or iPad, try the fixes below.
My Photos Will Not Upload
1. Check if you have enough space on iCloud
If you have updated to iOS 11/12, the two new formats HEVC and HEIF will cut half the storage of your photos. If you're not an early adopter, you should know that the 12-megapixel photos, live photos and 4K recordings will still take large space - generally the size of a Live photo (HDR) taken from iPhone is in the range of 3-4MB, 1MB larger than still photo.
Specifically, up to 2000 photos will consume iCloud 5GB storage and lead to iCloud storage full error. If your iPhone photos won't upload to iCloud, check Settings > iCloud > Storage.
2. Sign out iCloud and sign back in
Sometimes the basic solutions turn out to be something you may ignore. After I did a good deal of searches on various forums and found a user with photos not uploading to iCloud Photo Library citing that the Apple Support told him to sign out of iCloud and then sign in. And the fix works for many users. Another similar fix is to toggle iCloud Photos on and off, that also helps!
3. Reset your network settings
As photos to iCloud uploading involves the network, Wi-Fi is a must-check when iCloud Photo Library not uploading photos or icloud photos not syncing to Mac. You can either forget this network and rejoin: Settings > Wi-Fi > Choose Home Network> Forget This Network > turn off Wi-Fi from your iPhone > turn it on and rejoin the Wifi network; or reboot your home Wi-Fi. Then try again to see if your iCloud photo uploading is back to normal.
4. Make sure your device has enough space
For some users who is uploading their photos to iCloud for freeing up space on their device can hardly have any extra room. But many users don't know that if your device is too crowded, the problem of 'iCloud backup couldn't be completed' also happens. Though Apple support page doesn't specify this, at least 500MB of storage is required on the iPhone or iPad. So you may need to free up space on iPhone iPad if necessary.
5. Clear your camera roll
A user also mentioned that a full deletion of the photos from the device will help fix iCloud photos not syncing to Mac. Specifically, you need to transfer all photos from iPhone to Mac, clear out your camera roll on iPhone and then re-import the pictures you want to upload to iCloud. To do this, you can use Image Capture, iTunes or a third-party iPhone file manager.
6. Turn to other photo backup solution
As mentioned above, iCloud is great for uploading a small group of photos taken on a device and is usually slow for a bulk upload. Even if you don't have problem with photos not uploading to iCloud Photo Library, it's quite common that it takes hours and days for uploading thousands of photos.
Photos Not Uploading From Iphone
'My 5000 + photos were uploaded in a couple of days.', 'For me it took 4-5 days to upload about 1700 photos.', 'It took me about 5 days to complete'... If you're tired of hours and days of babysitting during which you have to make sure the battery is full, the photos app open and the Wi-Fi is connected, and if you simply want to free up more space and keep your photos safe, you can backup them to your computer with a third-party app. The app for me is called MacX MediaTrans.