Check your storage in Settings

Open Settings on your iPhone, then tap General, then iPhone Storage. The screen shows a bar at the top with your total capacity and how much space is used. Below that is a list of every app on your phone, sorted by size from largest to smallest. This is the fastest way to see what is taking up room.

The number next to each app shows how much space that app uses. This includes the app itself plus any data it has stored — photos in the Photos app, messages in Messages, cached videos in YouTube, and so on. If an app shows 5 GB but you barely use it, that is a candidate for deletion.

Tap any app in the list to see more detail. For some apps like Photos or Mail, you will see a breakdown of what is inside — how many photos, how many emails, how much video. For others, the detail screen just shows the size and the last time you used it.

Key Takeaways

  • Settings > General > iPhone Storage shows every app and how much space it uses, sorted largest to smallest.
  • The Photos app usually takes the most space; check how many old photos and videos you are keeping before deleting anything.
  • Cached data from streaming apps, browsers, and messaging apps adds up fast and can be cleared without losing your account or messages.
  • iCloud Photos and iCloud Drive let you move photos and documents to cloud storage, freeing up phone space while keeping them accessible.

Understand what "Documents and Data" means

When you look at an app in iPhone Storage, you may see two numbers: the app size itself, and a separate number for "Documents and Data." Documents and Data is anything the app has saved on your phone that is not the app code itself — cached videos, downloaded files, message history, contact backups, or temporary files the app created while running.

For example, WhatsApp might show 500 MB for the app and 2 GB for Documents and Data. That 2 GB is your message history, downloaded photos from chats, and voice message files. Deleting the app removes both numbers. Offloading the app (see below) removes the app code but keeps the Documents and Data, so you can reinstall without losing your messages.

Offload apps instead of deleting them

If you want to free up space but keep your data, offload the app instead of deleting it. In iPhone Storage, tap the app name, then tap Offload App. This removes the app code but keeps your Documents and Data on the phone. When you reinstall the app later, your messages, settings, and saved files are still there.

Offloading is useful for apps you use occasionally but not often. Games, seasonal apps, or work tools you only need at certain times are good candidates. The app icon stays on your home screen with a small cloud icon on the corner, and tapping it reinstalls the app automatically.

If you delete the app entirely instead, you lose both the app and its data. You can reinstall the app from the App Store, but your saved data inside it is gone. Some apps back up their data to your iCloud account (like Notes or Reminders), so reinstalling restores everything. Others do not, so you lose it.

Move photos and videos to iCloud Photos

Photos and videos usually take the most storage on an iPhone. If your Photos app shows several gigabytes, the fastest way to free space is to turn on iCloud Photos. Go to Settings > [Your Name] > iCloud > Photos, then turn on iCloud Photos.

When iCloud Photos is on, your phone stores full-resolution originals in iCloud and keeps optimized (smaller) versions on your phone. You see all your photos in the Photos app as if they were local, but they take up far less space. If you need the full-resolution version, your phone downloads it when you open the photo.

This requires an iCloud+ subscription (50 GB, 200 GB, or 2 TB per month) or a free iCloud account with 5 GB of storage. If you have a free account and turn on iCloud Photos, your 5 GB covers both photos and other iCloud data like Mail, Contacts, and Reminders. A 50 GB iCloud+ plan costs $0.99 per month and gives you room for thousands of photos.

Clear cache and temporary files from apps

Apps create temporary files while you use them — cached web pages in Safari, downloaded video previews in TikTok, temporary image files in messaging apps. These files can add up to several gigabytes over time. You cannot see them in iPhone Storage, but you can clear them by offloading and reinstalling the app, or by going into the app's own settings.

Some apps have a "Clear Cache" or "Storage" option in their settings. Open the app, go to its settings or preferences, and look for options like "Clear Cache," "Storage," "Data," or "Manage Storage." Clearing cache removes temporary files but keeps your account, messages, and saved data intact.

For apps without a built-in clear option, offloading the app removes the cache along with the app code. Reinstalling restores the app but not the cached files, so you free up that space. This is safe — cached files are meant to be temporary and can be recreated.

Use iCloud Drive for documents and files

If you store documents, PDFs, or other files on your phone, moving them to iCloud Drive frees up local storage. Go to Settings > [Your Name] > iCloud > iCloud Drive and turn it on. Then open the Files app, and you can move documents from "On My iPhone" to "iCloud Drive."

Files in iCloud Drive stay accessible from your phone, your computer, and the web. Your phone stores only the files you use most often locally; others are stored in iCloud and downloaded when you open them. This works the same way as iCloud Photos — you see all your files, but they do not all take up phone space.

Like iCloud Photos, iCloud Drive counts against your iCloud storage limit. A free account has 5 GB total for all iCloud data. If you need more, iCloud+ plans start at $0.99 per month for 50 GB.

Delete old messages and attachments

The Messages app often holds gigabytes of photos, videos, and files people have sent you. Go to Settings > General > iPhone Storage, tap Messages, and you will see how much space it uses. To free up space, open the Messages app, swipe left on a conversation, and tap Delete. Deleting a conversation removes all messages and attachments in it.

If you want to keep some messages but delete old ones, open a conversation, tap Edit in the top left, select the messages you want to remove, and tap Delete. You can also set Messages to delete old messages automatically: go to Settings > Messages > Keep Messages and choose 30 Days or 1 Year. Messages older than that date delete automatically.

Before you delete, remember that deleting a message removes it from your phone permanently. If you want to keep a photo or important message, save it to your Photos app or Notes app first.

Frequently Asked Questions

Why does my iPhone say I have no storage when Settings shows I have space?

iOS reserves space for system updates and temporary operations. If your free space is below 1 GB, your phone may refuse to install updates or run certain features, even though Settings shows available space. Delete or offload apps, clear cache, or move photos to iCloud until you have at least 2 GB free.

Does turning on iCloud Photos delete my photos from my phone?

No. When you turn on iCloud Photos, your phone keeps optimized versions of your photos locally and stores full-resolution versions in iCloud. You see all your photos in the Photos app. If you want to delete local copies to save space, go to Settings > General > iPhone Storage > Photos and tap Offload, but this is separate from turning on iCloud Photos.

Can I see what is using storage in iCloud, not just on my phone?

Yes. Go to Settings > [Your Name] > iCloud > Manage Storage. This shows what is using your iCloud account space — Photos, Mail, Backups, Documents, and other apps. Tap any category to see details and delete items if you want.

What happens if I offload an app and then run out of iCloud storage?

Offloading removes the app code from your phone but keeps its data stored locally. Your iCloud storage limit does not affect offloaded apps. If you run out of iCloud space, you cannot back up new data to iCloud, but offloaded apps still work and your saved data stays on your phone.

Is it safe to delete the cache from apps like Safari or Chrome?

Yes. Cache is temporary data meant to load websites faster. Deleting it removes that speed benefit temporarily, but it does not delete your bookmarks, passwords, or browsing history. Websites will load slightly slower the first time you visit them after clearing cache, then speed up again as new cache builds.