I think most Mac people sync their iPhone photos through iCloud to their Mac and other iDevices. Then again, I know several people (mostly younger folks) that either do not have a Mac or just do not wish to sync their photos through iCloud. So, what happens to these folks is their photos pile up and their iPhone become full. If you are in this category, you may need to move some or all of your iPhone photos off your phone. Here is how you do that.
Admittedly, to achieve this you do need a Mac computer. It might be a good time to buy a used one off eBay or somewhere else on the Internet. You begin this process by connecting your iPhone to a Mac computer via a lightning cable. Once it is connected, open the Image Capture App and click on your iPhone in the left column.
Pay special attention to the “Download” and “Download All” buttons in the bottom-right corner of the window. Apple is strongly encouraging you to download to a Mac the photos you are going to remove from your iPhone. If you are removing all the photos, then click on “Download All” the photos. This may take some time.
Once the photos in question are downloaded, then either “Select All” to remove all photos or Command-Click on the photos you wish to remove to select them.
Once you have the photos selected, click on the “Trash” icon in the menubar. You will receive the typical warning message.
When you click on “Delete”, the photos in question are gone.
I don’t think I need to tell you to proceed with caution removing photos from your iPhone. But, Apple provides a way for you to save those memories.