You open your iPhone to take a quick video, and instead of the camera, you get a popup: "Storage Almost Full." This is one of the most frustrating experiences for any iOS user. If you go to Settings > General > iPhone Storage (see Apple's official guide), you are greeted with a colorful bar chart. But what do those colors actually mean, and what is taking up all your space?
How to Read the Storage Graph
To find out what is eating your storage, go to Settings > General > iPhone Storage. Wait a few seconds for the colorful bar graph at the top of the screen to finish calculating.
The graph breaks your storage down by color:
- Red (Apps): This includes the apps themselves and the cache they generate (like offline Spotify music or Netflix downloads).
- Yellow (Photos): Your entire camera roll, including videos.
- Green (Messages): Text messages and all the photo/video attachments sent in group chats.
- Grey (System Data): Background files the operating system needs to function, plus temporary caches.
The App List
Directly beneath the graph, you will see a list of every app on your phone, sorted by size. The apps at the top of this list are the ones causing your problems.
If you tap on an app in this list, it breaks the size down into two categories:
- App Size: The actual code required to run the app.
- Documents & Data: The files you have generated or downloaded while using the app.
For example, the TikTok app size might be 300 MB, but its Documents & Data might be 5 GB because of cached videos. To clear it, you can delete the app and redownload it.
Apple's Built-in Recommendations
Right below the colorful graph, iOS usually provides automated "Recommendations" tailored to your specific phone. These are the easiest ways to free up space instantly.
- Review Large Attachments: Tapping this will show you the biggest videos sitting in your iMessage chats, allowing you to delete them in one tap.
- Recently Deleted Album: If you deleted photos but they are still in the 30-day waiting period, iOS will offer to wipe them permanently here.
- Offload Unused Apps: This tells your iPhone to automatically delete apps you haven't used in months while keeping your save data safe.
The Most Common Culprit: Photos
For 90% of iPhone users, the yellow "Photos" bar is the largest section of the graph. High-resolution photos and 4K videos fill up storage faster than anything else.
If your Photos app is taking up 40 GB, you need to clean it. The native Photos app makes finding the junk tedious, but you can use a tool like Swipe Photo Cleaner to speed up the process. It presents your camera roll full screen and lets you swipe left to delete blurry bursts and old screenshots, helping you shrink that yellow bar quickly and safely.