- Videos, photos, apps and chat media usually take the most space.
- Back up before you delete, so nothing important is lost.
- Avoid “cleaner” apps. Your phone’s own storage tools are safer.
The short answer
When your phone says storage is full, the quickest fix is to find the biggest items and move or delete what you no longer need. Start by checking what uses the most space, back up your photos and videos, then clear app data and downloads you do not need. You can often free several gigabytes in under half an hour without losing anything important.
Step 1: See what is using the space
- iPhone: open Settings, General, then iPhone Storage. It lists apps by size and suggests actions.
- Android: open Settings, then Storage. Many phones show a breakdown by images, videos, apps and files.
Look at the top of the list first. One or two items are usually responsible for most of the space.
Step 2: Back up before you delete
Copy your photos and videos to a computer, an external drive or a cloud service so that deleting them from the phone does not mean losing them. Our guide on how to back up your phone and laptop walks through the options. Check that the copy opens correctly before you remove the original.
Step 3: Clear the big items
| What to check | What to do |
|---|---|
| Photos and videos | Move to your computer or cloud, then delete from the phone. Videos take the most space. |
| Chat apps such as WhatsApp | Open the app’s storage settings and clear large videos and forwarded files you no longer need. |
| Unused apps | Uninstall apps you have not opened in months. On iPhone you can offload an app and keep its data. |
| Downloads | Delete old PDFs, installers and music you no longer use. |
| Offline maps and streaming downloads | Remove offline content you finished with. |
Step 4: Clear app cache and data carefully
Apps store temporary files, called a cache, to open faster. On Android you can clear the cache for a single app under its storage settings without losing your login or files. Be careful with “clear data”, because it can remove accounts, saved games and messages. On an iPhone, deleting and reinstalling an app clears its cache, but check that your data is backed up first.
Step 5: Use storage tools wisely
- Turn on the phone’s own suggestions, such as removing duplicate or old photos.
- If your Android phone has a memory card slot, move photos, music and downloads to the card.
- Avoid third-party “booster” and “cleaner” apps. Many show adverts, ask for broad permissions and do little that the phone cannot already do.
Stop it filling up again
- Set your camera to a lower video resolution if you rarely need the highest.
- Switch off automatic download of media in chat apps.
- Back up regularly and clear the phone each month.
- Keep at least 10 percent of storage free so the phone stays quick.
Quick checklist
- Check which apps and files use the most space
- Back up photos and videos first
- Clear chat media and unused apps
- Clear cache for single apps, not all data
- Skip cleaner apps and keep some space free
Key points to remember
A full phone is rarely a mystery. A few big files cause most of the problem, and a regular monthly clean-up keeps it under control. If the phone is also slow, read how to choose a good smartphone without overspending before you replace it.
