Quick Answer
To free up space on an iPhone, open Settings > General > iPhone Storage, apply Apple’s recommendations, and then clear the largest categories first. Offloading unused apps, turning on Optimize iPhone Storage for photos, deleting large message attachments, and removing downloaded videos recover the most space. System Data cannot be deleted manually, because iOS manages those files itself.
Key Takeaways
- Settings > General > iPhone Storage shows the available space, Apple’s recommendations, and a list of apps with the storage each one uses.
- Offloading an app frees the storage used by the app but keeps its documents and data, while deleting an app removes the app and its related data.
- Optimize iPhone Storage keeps full-resolution photos and videos in iCloud and space-saving copies on the phone; iCloud includes 5 GB for free.
- Deleted photos and deleted messages stay in Recently Deleted for up to 30 days, so the space is not released until that folder is emptied.
- Apple states that iOS removes cached and temporary files on its own when the device needs space, so there is no manual control for System Data.
How do you check what is taking up space on an iPhone?
To check what is taking up space on an iPhone, open Settings, tap General, and then tap iPhone Storage. Apple’s guide on how to check the storage on an iPhone and iPad explains that this screen shows recommendations and a list of apps with their storage usage, and the available storage appears at the top. Tapping an app’s name opens a detailed view with the options to offload or delete that app.
Apple groups iPhone storage into 9 categories. They are Apps, Photos, Media, Mail, Apple Books, Messages, iCloud Drive, Other, and System. The table below summarizes what Apple says each of the main categories contains and the most direct way to reduce it.
| Storage category | What it contains (per Apple) | Most direct way to reduce it |
|---|---|---|
| Apps | Installed apps and their content, files in “On My iPhone,” and Safari downloads | Offload or delete unused apps; remove downloads inside each app |
| Photos | Photos and videos stored in the Photos app | Turn on Optimize iPhone Storage; merge duplicates; empty Recently Deleted |
| Media | Music, videos, podcasts, ringtones, artwork, and voice memos | Remove downloaded episodes, songs, and videos you have finished |
| Messages | Messages and their attachments | Delete large attachments; set Keep Messages to 30 Days or 1 Year |
| Emails and their attachments | Delete old messages with large attachments | |
| Other (System Data) | Non-removable assets such as Siri voices, fonts, dictionaries, logs, caches, and the Spotlight index | No manual control; iOS clears caches when space is needed |
| System | Space taken by the operating system, which varies by device and model | Cannot be reduced |
What is the fastest way to free up space on an iPhone?
The fastest way to free up space on an iPhone is to use the recommendations at the top of the iPhone Storage screen and then work through the largest categories in order. Apple states that when storage is full, the device might offer recommendations for optimizing storage, and that a “Storage Almost Full” alert should be answered by checking those recommendations or removing content such as videos and apps.
Back up the iPhone to iCloud or to a computer before you delete anything, because several of the steps below remove content permanently once the Recently Deleted period ends. Then follow these 8 steps in order.
- Open Settings > General > iPhone Storage and note the available space and the 3 largest items in the list.
- Tap Show All next to the recommendations, read each description, and tap Enable or review the content that the recommendation offers to delete.
- Offload apps you rarely open by tapping the app in the list and choosing Offload App.
- Turn on Optimize iPhone Storage under Settings > [your name] > iCloud > Photos if you use iCloud Photos.
- Merge duplicate photos in Photos > Collections > Utilities > Duplicates.
- Delete large photo and video attachments from long conversations in the Messages app.
- Remove videos, podcasts, and music you downloaded for offline use inside the TV app and other streaming apps.
- Empty Recently Deleted in both Photos and Messages so the deleted items stop occupying storage.
Stop and reassess if the available space barely changes after these steps. That result usually means the remaining usage sits in a category the user cannot clear directly, which the System Data section below explains.
What is the difference between offloading and deleting an app on iPhone?
Offloading an app on iPhone frees up the storage used by the app but keeps its documents and data, while deleting an app removes the app and its related data. Apple describes both options in the detailed view under Settings > General > iPhone Storage. Offloading is therefore the safer choice for an app you may need again, such as an airline app or a game with saved progress.
The iPhone can also offload apps automatically. Apple’s user guide page on managing storage on iPhone says that when storage is low, the iPhone can remove unused apps while keeping their data, and that the app icon stays on the Home Screen with a cloud symbol that reinstalls the app when tapped. To turn the setting on, go to Settings > Apps > App Store and enable Offload Unused Apps.
Deleting is the better option when the app’s own data is the large part. Apple’s instructions for removing or deleting apps from iPhone note that data an app stored in iCloud is not deleted with the app, and that available storage may take a moment to update afterward.
How do you free up photo and video space without deleting photos?
To free up photo and video space without deleting photos, turn on Optimize iPhone Storage in the iCloud Photos settings. Apple explains in its guidance on managing photo and video storage that photos and videos are stored on the device in their original, high-resolution version by default. With Optimize Storage turned on, the full-resolution files are stored in iCloud and space-saving copies are kept on the device when needed.
- Open Settings, tap [your name], tap iCloud, and then tap Photos.
- Turn on Sync this iPhone.
- Tap iPhone Storage (in iOS 27 or later) and make sure Optimize iPhone Storage is turned on.
The main limitation is that this method moves the storage problem to iCloud. Apple gives every account 5 GB of iCloud storage for free, which a large photo library exceeds quickly. As of October 2026, Apple’s iCloud+ pricing page lists US plans at $0.99 per month for 50 GB, $2.99 for 200 GB, and $9.99 for 2 TB, with tax added in some states. Readers who prefer not to pay can transfer photos and videos to a computer instead, and our guide to converting HEIC photos to JPG on Windows helps when those files need to open on a PC.
Deleting unwanted photos still helps, but two details affect the result. Apple’s page on deleting photos on an iPhone states that deleted items go to the Recently Deleted album for 30 days, so the space returns only after that period or after you delete them there manually. The same page warns that when iCloud Photos is on, deleting a photo on one device deletes it on every device signed in to the same Apple Account. Removing photos from the iPhone is therefore not a way to keep them only in iCloud.
How do you clear Messages attachments and Safari data on iPhone?
To clear Messages attachments on iPhone, open the conversation, tap the contact or group icon at the top, tap a category such as Photos, and then select and delete the attachments you no longer need. Apple documents these steps in its guide to deleting messages and attachments in Messages.
The Messages app can also remove old conversations on an ongoing basis. Go to Settings > Apps > Messages, scroll down, tap Keep Messages, and choose 30 Days or 1 Year instead of Forever. Apple attaches an important warning to this setting: conversations, including all attachments, are automatically removed after the chosen period. Save any photos or documents you want to keep before changing it, because the setting does not distinguish between important and unimportant threads.
Safari data is the third place to look. Apple’s instructions for deleting Safari history, cache, and cookies on iPhone give two paths:
- Go to Settings > Apps > Safari and tap Clear History and Website Data to remove history, cookies, and cache together.
- Go to Settings > Apps > Safari > Advanced > Website Data and tap Remove All Website Data to clear cookies and cache while keeping the browsing history.
What is System Data on iPhone, and can you delete it?
System Data on iPhone is the storage category that holds files iOS needs but that do not belong to a single app, and it cannot be deleted manually. Apple’s storage documentation describes this category, labeled “Other” on its support page, as non-removable mobile assets such as Siri voices, fonts, and dictionaries, along with non-removable logs and caches, the Spotlight index, and system data such as the Keychain and CloudKit database.
System Data changes in size because part of it is cache. Apple explains that the device creates cached files when you stream or view content so that the content loads faster the next time, and that the device removes these files when it needs more space. In Apple’s words, the device removes cached and temporary files “so you don’t have to.” A large System Data figure on a phone with plenty of free space is therefore expected behavior and not a fault.
The practical response is to reduce the content you can control and let iOS manage the rest. Clearing Safari website data, removing streaming downloads, and deleting message attachments shrink the caches those apps generate. Apple does not document any manual method for clearing System Data. Contact Apple Support if the iPhone remains full after you have removed apps, photos, and messages and the remaining usage sits almost entirely in System Data, because that pattern is not something a user can resolve through Settings.
How do you keep an iPhone from filling up again?
To keep an iPhone from filling up again, turn on the automatic options and review the iPhone Storage screen periodically. There are 4 settings that do most of the work. They are Offload Unused Apps, Optimize iPhone Storage, a Keep Messages limit, and regular cleanup of downloaded video.
- Offload Unused Apps (Settings > Apps > App Store) removes apps you do not use while keeping their data.
- Optimize iPhone Storage (Settings > [your name] > iCloud > Photos) keeps smaller photo copies on the device.
- Keep Messages (Settings > Apps > Messages) limits message history to 30 days or 1 year.
- Downloaded videos in the TV app and other streaming apps should be removed after you have watched them, as Apple’s user guide recommends.
Do not confuse iPhone storage with iCloud storage. Apple’s page on managing iCloud storage treats the two as separate: the device capacity is fixed when you buy the phone, while iCloud storage is an account allowance that can be upgraded. Buying more iCloud storage frees space on the phone only when a feature such as Optimize iPhone Storage moves the full-size files off the device.
Storage is only one part of iPhone upkeep. Our related guides explain why an iPhone overheats and how to fix it, what to check when an iPhone will not charge, and how Apple Intelligence works on iPhone.
Frequently Asked Questions
Why is my iPhone storage full when I have iCloud?
iPhone storage can be full even with iCloud because device storage and iCloud storage are separate. iCloud frees space on the phone only when a feature such as Optimize iPhone Storage keeps the full-resolution photos in iCloud and space-saving copies on the device.
Does offloading an app delete its data on iPhone?
No, offloading an app on iPhone does not delete its data. Apple states that offloading frees up the storage used by the app but keeps its documents and data, and tapping the app icon reinstalls the app.
Can you delete System Data on iPhone?
No, System Data on iPhone cannot be deleted manually. Apple says the device removes cached and temporary files on its own when it needs more space, so the practical step is to clear app content such as Safari website data and message attachments.
Do deleted photos still take up space on iPhone?
Yes, deleted photos still take up space on iPhone until they leave the Recently Deleted album. Apple keeps deleted photos and videos there for 30 days, and you can remove them sooner by deleting them from that album.
How much free iCloud storage do you get with an iPhone?
Every Apple Account gets 5 GB of free iCloud storage. As of October 2026, Apple lists US iCloud+ plans starting at $0.99 per month for 50 GB, with tax added in some states.