From the iPhone 8 to the X, all the way back to the 7. Here are the details…
The iPhone 7 vs 8 (regular and Plus) is a bit more nuanced.
Biggest difference is the storage. The iPhone 8 can now be upgraded to 256gigs, for $849. But there is no 128gig middle. It skips from 64gigs to 256gigs for some reason. The iPhone 7 has a 128gig for $649.
Then the iPhone X jumps to $900 for a 64gig and over $1k for 256gigs.
The 8 is a tad larger/heavier than the 7- not very noticeable. Both 8 and 8 Plus are practically identical to the 7.
It is water resistant, which they say you could save your phone if you accidentally jump into a pool with it in your swimsuit pocket.
Some say you could shoot pics underwater. I’d wait for the YouTube reviews first before you try.
No Face ID, the 8 still has the Touch button. And like the 7, it combined the headphone jack and Lightning port. So you might need the adapter for your wired headphones. But the adapter should be included.
The iPhone 8 has also upped its memory to 3 gigs, with a six core CPU. Not much of a difference though…
Batteries are the same between 7 and 8, but it is wirelessly charging. Not sure how fast wireless charging will work. Watch for YouTube videos.
Bottom line: if you have the iPhone 7, upgrading to the 8 is a bit useless. Upgrading to the X could be worth it.