Cache rules everything around me, including my phone and yours.
Cache is all the data your phone acquires and stores as you visit websites and use apps, just in case you need it again. In theory, all this data collection will speed up future visits. But over time, cache can build up to the point where it slows down (and sometimes overheats) your phone.
Clearing the cache in your phone's browsers and apps can improve its performance. It’s an easy-enough task that you should perform once every few months to keep your phone functioning well.
Browsers
Let’s start with browsers. After you’ve closed all those tabs that you’ve lost track of (don’t worry, everyone does it), you’re going to delve into the data they’ve stored.
For Safari, go to Settings > Safari > Clear History and Website Data. Here, you can choose whether to clear the last hour, today, today and yesterday, or all history. (There's also the option to close all your tabs from this menu.)
For Chrome, open the app and select More > Clear Browsing Data. You’ll be able to select what you want to remove. When you’re done, tap Clear Browsing Data > Done.
For Firefox, open the app and select Settings > Privacy > Data Management. Make sure Cache is toggled on; you can also clear browsing history, cookies, online website data, tracking protection and downloaded files. Select what you want and tap Clear Private Data at the bottom.
Apps
You can’t clear individual app cache on an iPhone but if you offload an app, it will achieve the same thing. Go to Settings > General > iPhone Storage. You’ll be able to see what apps you use the least. Tap any apps you don’t need on your phone right now and select Offload App. The app will remain on your home screen, but you'll need to tap to re-download to get back in.
(Credit: PCMag/Apple)