These games grow, quietly and relentlessly, and the settings screen does not distinguish between the cache you can safely delete and the save file you cannot.
Why the growth happens
The download from the store is a shell. Once running, the game fetches the rest: level packs, seasonal art, event backgrounds, character sets, sound banks and the assets for advertising formats it might need to display.
Very little of that is ever removed. A Christmas event from two years ago frequently still has its artwork sitting on the phone, because deleting downloaded content risks breaking a running install and studios reasonably prefer to leave it alone.
The three kinds of space, which look identical
- The app itself. The code and the base assets. Reinstalling replaces this and it is never where the storage problem lives.
- Cache. Downloaded content that can be fetched again: event art, video ad assets, images. Safe to delete. This is usually the majority of the growth.
- Data. Settings, and on games without cloud saving, your entire progress. Deleting this on such a game is indistinguishable from starting over.
Android presents cache and data as two separate buttons, which is helpful and also dangerous, because they sit next to each other and one of them is irreversible. iOS presents neither, offering instead Offload App, which removes the app but keeps its data.
Before clearing anything on Android, check whether the game has your progress attached to an account. If it does not, Clear data is the same action as deleting your save, and there is no confirmation step that explains this.
Doing it safely on each platform
Android. Settings, then Apps, choose the game, then Storage. Clear cache is safe and can be done as often as you like; the game re-downloads what it needs. Clear data or Clear storage resets the app to a fresh install and, on a game without cloud saving, ends your progress.
iOS. Settings, then General, then iPhone Storage, then the game. Offload App removes the application and keeps its documents and data, so reinstalling restores your position; Delete App removes both. There is no cache button, and the usual way to shed accumulated cache on iOS is to offload and reinstall.
Deciding what to remove
Sort the storage list by size and look at the top five. In practice the honest questions are: have I played this in the last month, is my progress attached to an account, and would I be upset to lose it. A game you have not opened in six months, whose progress is on an account, can be deleted outright and restored later in minutes.
The one that deserves care is the game you play daily whose progress lives only on the device. That is worth linking to an account before touching anything, which is covered in the guide on cloud saves.
Updates, and controlling when they happen
Updates in this genre are frequent and often large. Two settings make them less disruptive.
- Wi-Fi only. On Android, Play Store settings, Network preferences, Auto-update apps over Wi-Fi only. On iOS, Settings, App Store, and turn off Automatic Downloads on mobile data.
- Per-app auto-update. Android allows this from the game's own store listing, through the menu in the corner. iOS does not offer it per app.
Turning updates off entirely is a short-term measure rather than a policy. These games increasingly refuse to connect to online features on an old client, and an unpatched game eventually stops working rather than merely staying the same.
A reasonable maintenance routine
Once every few months: sort by size, clear the cache on the two or three largest games, offload anything not played recently, and confirm that the games you do play are attached to an account. That takes about five minutes and prevents the situation where a phone is full and the fastest apparent fix is the one that deletes a year of progress.