If the Photos app is a big factor, turning on optimized storage for iCloud Photos can help out.
First things first, to check what is eating up your storage space on your Mac, head to → About This Mac→ Storage. Photos and videos are usually some of top usage categories for many Mac users. Read on to see if this solution could be a good fit for you. Is your Mac running low on storage space? One way to easily free up room is by utilizing iCloud Photos and the optimize storage feature.