When you need to free up room on your iOS device, the first place to look is the Photos app. But you don't have to set up any elaborate plans to remove images from your phone to park them elsewhere — not if you're using the iCloud Photo Library. An obscure control in the Photos settings called Optimize iPhone Storage stores only the thumbnails, not your original photos and videos, letting you save space while keeping your images accessible. As long as you have enough space on iCloud to store your originals, you can keep as many photos and videos as you want without maxing out your handset.
Apple's iCloud Photo Library is a huge convenience — it stores and displays your photos on all your devices. If you're running out of space on some of those devices, deleting photos from your camera roll also deletes them everywhere, which is not what you want.
Set up iCloud Photo storage
Instead of deleting images, you can save on the space they take up when stored at their original resolution. With iOS 15, you can enable the Optimize iPhone storage control in your Photos settings, which lets your iPhone convert your high-resolution images into lightweight thumbnails. The original photos still reside in iCloud, and you can also back them up on your Mac or an external drive. Using this optimization control gives you the best of both worlds: All your photos are available to you whenever and wherever you want to see them, and you get to salvage your storage space. Here's how to set it
Step 1: Tap Settings > [your name].
Step 2: Tap iCloud > Photos.
Step 3: Switch on iCloud Photos.
Step 4: Check Optimize iPhone storage.
If you check Download and keep originals, all photos you shoot on your iPhone stay on your handset in full resolution. Plus, any photo that you take, store on your Mac, or otherwise store on your iCloud Photo Library will also download to your iPhone in high resolution.
Optimize iPhone storage will not immediately change your images into thumbnails. You could see a combination of thumbnails interspersed with original, high-resolution images if your phone has enough memory to support them.
Your phone’s storage works in the background to keep track of images you’ve recently viewed compared to how much storage you use for apps and downloads. It will always keep the most recent media shot or viewed in high resolution. Other factors involved include the amount of storage space and memory that your phone has and the number of images on your phone.
People with lots of space on their phones will have more high-resolution images and videos stored locally than those with less space. Don’t worry about losing your high-resolution images when your phone compresses them to save space. You can always revert compressed photos to their initial form by downloading them. You will see the compressed images downloading in real-time, as they have a download circle at the bottom right as they flow in from iCloud.
