Can anyone explain to me why my Photos library is 17GB when I only have some 3400 pictures and videos in it? I have maybe two or three home videos over ten minutes and my other videos (definitely <50ish) are all around a minute in length. I don't use live photos. This just baffles me, as my Photos library is nearly 20 GB on both my iPhone and my MacBook air and it's taking up a considerable chunk of space on both of them. How in the WORLD do I find out why it's like this? It's driving me ******* crazy. Thanks for your help! I have a four-month old iPhone 6S after upgrading from a 5s. It's running iOS 9.3.4. My MacBook Air is an early 2015 model and running OSX Yosemite 10.10.4. I just saw a software update for my phone and I didn't know until just a few days ago that El Capitan even existed (don't ask ), but I don't think that's the root cause of this problem and I intend to update soon.