Why is my iPhone backup taking up all the space on my laptop?

Backups can be tricky! iTunes expends space for processing during the transfer, acting like it's sorting things out in the background. It's similar to needing extra room to fit various sized boxes into a bigger one. So, yeah, more free space is essential during this process!

You might want to clear out some stuff on your laptop first. Even if you think you have enough space, iTunes often needs additional free space to unpack and optimize the backup files. It’s a good rule of thumb to have at least 20% more space available than the size of the data you're backing up.

It sounds like your laptop needs more free space than just what your phone uses for the backup. When backing up, it's not just a straightforward transfer; the backup process requires extra space temporarily to handle everything without corruption. Moving to an external hard drive could be a good move for you, as they’re pretty cheap these days.

Unfortunately, it looks like you need a larger storage option. You'll likely need to upgrade to a laptop or external drive with at least 1TB of capacity. That ensures you have enough room for the backup process and avoids any issues if the size of the files differs.