How to Quickly Free Up Large Amount of Storage Space on Your Mac
Of all the prompts an operating system can throw at you, "not enough space" is probably the most dreadful and annoying. Optimizing iCloud Photos gives us a lot of free storage space to work with. If you need even more space, you could completely delete the Photos library, do whatever you need to do with the space, and then create a new Photos library from scratch once you are done.