What makes iPhone run slow?

I've cleaned my iPhone twice (I uninstalled 2 apps) but it's still running slowly.

There are nearly to many potential reasons for a slow phone to even list. Some of the obvious ones are:

• Programs running in the background
• not  enough memory
• poor/weak service
• updates

Have a read here: https://www.macworld.co.uk/how-to/iphone/speed-up-slow-iphone-3463276/

There are nearly to many potential reasons for a slow phone to even list. Some of the obvious ones are:

• Programs running in the background
• not  enough memory
• poor/weak service
• updates

Have a read here: https://www.macworld.co.uk/how-to/iphone/speed-up-slow-iphone-3463276/

Thanks.i deleted some useless apps and made a little space.

Could also be due to the battery. If you have a phone that is at least a year old, then performance could have already been affected by the aging battery, Apple has confirmed previously that it does this.