How to free up storage on your phone in 15 minutes

"Storage almost full" always shows up at the worst moment: mid-video at a birthday party, or the night before a trip. Most people start deleting apps at random and win back a few hundred megabytes. The real space is usually hiding in four places, and you can clear most of it in fifteen minutes.

First, see what's actually taking the space

Don't guess. Both platforms will show you.

• iPhone: Settings > General > iPhone Storage. Wait a moment for the colored bar to load, then scroll the list. Apps are sorted by size, including their data.
• Android: Settings > Storage. Menus differ by maker, but you'll see categories like Images, Videos, Apps and Documents. Many phones also include Google's Files app, whose Clean tab suggests junk files, old screenshots, duplicates and large files.

The usual culprits, in rough order:

1. Videos. A minute of 4K video can take hundreds of megabytes.
2. Message attachments. Every photo, video and voice note anyone ever sent you, stored inside the messaging app.
3. Downloads. PDFs, installers and saved videos from years ago.
4. Trash folders. Deleted photos still use space until the trash empties.

Delete the big things you don't need, not the small things you do.

The 15-minute cleanup order

Work top to bottom. The early steps free the most space for the least risk.

1. Minutes 1–3: Review large attachments. On iPhone, open Messages in the iPhone Storage list and tap Review Large Attachments. Swipe to delete old videos and GIFs. On Android, open your messaging app's settings or the Files app's large files view.
2. Minutes 3–5: Set old messages to expire. On iPhone, find Keep Messages in the Messages settings (under Settings > Apps > Messages on recent versions) and choose 1 Year or 30 Days instead of Forever. This permanently removes older threads, so screenshot anything you want to keep first.
3. Minutes 5–8: Offload or delete apps you don't use. On iPhone, tap an app in the storage list and choose Offload App. The app goes, but your documents and data stay, and the icon remains for a quick reinstall. You can also turn on Offload Unused Apps. On Android, sort by size and uninstall, or use the Files app's unused apps suggestion.
4. Minutes 8–11: Clear Downloads. Open Files (either platform), go to Downloads, sort by size, delete what you don't recognize needing.
5. Minutes 11–13: Thin out videos. Sort your photo library by media type and delete the shaky, duplicate and accidental clips. Keep the one good take.
6. Minutes 13–15: Empty the trash. On iPhone, Photos > Recently Deleted holds items for 30 days, then deletes them for good; empty it now to reclaim space immediately. On Android, empty the trash in your gallery or photo app and in the Files app.

Before you delete photos, back them up

Clearing space and keeping memories aren't in conflict if you have a backup. Cloud photo libraries can keep a smaller copy on the phone and the full version online, but a cloud sync isn't the same as a backup: delete a photo on the phone and it usually disappears everywhere. Apple's free iCloud tier is 5 GB, which fills quickly, so check what plan you're on before trusting it. Copy anything irreplaceable to a computer or external drive too.

If you're tidying a phone for a parent, pair this with our checklist for setting up a phone for an aging parent.

Keep it from filling up again

• Turn off auto-saving media in group chats that send dozens of photos a day.
• Stream music and video instead of downloading, unless you're about to fly.
• Do this cleanup every three months. Put a repeating reminder on your calendar.

Fifteen minutes four times a year beats a panic purge the next time you're recording something you can't redo.