why is my iphone lagging so much
My iphone is constantly lagging when it comes to apps, messages, and just about everything. It's also been freezing a lot lately and not letting me use my apps properly
iPhone 5s, iOS 8.3
First, reset the phone by holding the sleep and home button for about 10sec, until the Apple logo comes back again. You will not lose any data by resetting, but it can cure some glitches.
If this does not work, restoring the phone would be the next step:
How to erase your iOS device and then set it up as a new device or restore it from backups
If still no luck, and to make sure that this is not software related, set it back to factory settings, without using any backup data afterwards. Set up the rest of the personal settings manually and test the phone.
If the phone works, restore from the latest backup. If the problem comes back, the backup data contained corrupt data, causing your issues.
Use iTunes to restore your iOS device to factory settings - Apple Support