What Is “Other” Storage on iPhone and How Do You Reduce It?

Open your iPhone storage screen and you may find a mysterious grey block labelled “Other” or “System Data” eating 10, 20, or even 30 gigabytes. Unlike apps or photos, you cannot open it, browse it, or delete it directly, which makes it one of the most frustrating parts of owning an iPhone. This guide explains what that space actually contains and the realistic ways to shrink it.

Quick Answer

“Other” storage (called System Data in newer iOS versions) is a bucket for caches, temporary files, Siri voices, fonts, logs, message attachments, and downloaded software update files. It grows and shrinks as iOS works. You cannot delete it directly, but restarting the phone, clearing Safari data, trimming Messages, and streaming rather than downloading media will usually bring it down over a few days.

What Is Inside “Other” Storage?

iOS puts everything that does not fit a neat category into this one bucket. Typical contents include:

• Caches from apps and the system, such as images Safari and social apps keep for faster loading.
• Temporary files created while streaming music and video, so playback is smooth.
• Siri and dictation voices, plus downloaded fonts and language packs.
• System logs and diagnostic files, especially after crashes or updates.
• Downloaded iOS update files waiting to be installed, or leftovers from a failed install.
• Mail and message data that does not count neatly under those apps.

Because caches are useful, a healthy iPhone always carries some “Other” storage. A few gigabytes is normal. It only becomes a problem when it balloons far beyond that and starts blocking photos, apps and updates.

Step-by-Step: Bring “Other” Storage Down

1. Restart your iPhone. A restart clears many temporary files and forces iOS to tidy up. Check the figure again afterwards; it often drops immediately.
2. Install any pending update, or delete a stuck one. In Settings > General > iPhone Storage, a waiting iOS update file can be several gigabytes. Install it or delete it.
3. Clear Safari. Go to Settings > Apps > Safari > Clear History and Website Data to drop one of the biggest caches.
4. Trim Messages. Old conversations with videos count partly here. Set Keep Messages to one year, or manually remove the largest threads.
5. Stream instead of downloading. Downloaded music and video libraries encourage large caches; streaming apps still cache, but far less aggressively.
6. Give it a day. iOS cleans caches when storage is tight and the phone is idle and charging. The number often falls overnight after you have freed some space elsewhere.

Why Does It Keep Growing Back?

Because caches refill by design. Every photo-heavy feed you scroll, every song you stream, and every map you load stores temporary data so the next visit is faster. The system is supposed to balance this against your free space, and on a phone with plenty of room it lets caches grow larger, which is why a 256 GB phone may show more “Other” than a 64 GB one. That is not a fault; it is the phone using spare space productively. The real warning sign is “Other” growing while your free space is nearly gone.

The Last Resort: Backup and Restore

If “Other” storage has swallowed an unreasonable share of a nearly full phone and nothing else works, a full backup followed by erasing and restoring the phone gives the system a completely clean start and almost always shrinks the category dramatically. This is a serious step that takes an hour or more, so treat it as the final option rather than the first. Back up to iCloud or a computer first, and make sure you know your Apple ID password before you begin.

If storage pressure is your wider problem, our guide on freeing up iPhone storage without deleting photos covers the other big wins, and Apple’s official iPhone User Guide explains how the storage screen categorises your data.

Mistakes to Avoid

Do not waste money on cleaner apps that claim they can delete “Other” storage for you. iOS sandboxes every app, so a cleaner cannot reach system caches at all. Avoid the internet tip of changing the date and time to trick the system into cleaning; it breaks more than it fixes, including message order and app logins. And do not judge success in the first five minutes after a clear-out, because the storage screen itself takes time to recalculate.

Which Apps Feed “Other” the Most?

Some habits grow System Data faster than others, and knowing them helps you target your efforts. Heavy video streaming fills temporary playback caches. Messaging apps with constant photo and video sharing build large stores of media data that do not always sit neatly under the app’s own name. Safari with hundreds of tabs and a long history holds more cached website data than most people expect. Music apps that stream at high quality cache aggressively, and podcast apps can leave behind partial downloads and artwork. Maps and navigation apps store offline areas and route data too.

You do not need to give any of these up. The point is that if your “Other” figure is large, one of these habits is usually responsible, and the corresponding clear-out, closing ancient Safari tabs, deleting watched downloads, trimming message threads, is the lever that actually moves the number. Randomly deleting small apps while a 12 GB cache survives untouched is why many clear-outs feel pointless. Match the fix to the habit, and System Data responds surprisingly well.

Conclusion

“Other” or System Data is not a virus or a fault; it is your iPhone’s working space, full of caches and temporary files. Keep it in check with restarts, a Safari clear-out, trimmed messages, and finished updates, and it will settle to a sensible size. Only reach for the full backup-and-restore when the number stays stubbornly huge on a nearly full phone.

Reading the Number Sensibly

A final word of perspective: the storage screen’s figures are estimates that the phone recalculates continually, and the “Other” number can swing by gigabytes between one glance and the next as caches are built and purged. Judge it over days, not minutes, and judge it against your free space rather than as a bare figure. Twenty gigabytes of System Data on a 512 GB phone with 300 GB free is a non-event. The same figure on a 64 GB phone with 1 GB free is an emergency. Context, not the raw number, is what should drive your response.

One Final Tip

Screenshot your storage screen today, with the date in mind, and again in a month. Two snapshots tell you whether System Data is stable, slowly growing with a habit you can identify, or spiking around updates and then recovering. That tiny bit of evidence turns every future storage worry into a quick comparison instead of a guessing game.

Frequently Asked Questions

How much “Other” storage is normal?

Anywhere from about 2 GB to 15 GB can be normal depending on how you use the phone and how large its storage is. Regular streaming, heavy messaging and lots of apps push it higher. Concern starts when it crowds out your free space.

Why did “Other” jump after an iOS update?

Updates download a large installer file, generate logs, and rebuild caches and indexes afterwards, all of which land temporarily in System Data. It normally shrinks again over the following days as the phone cleans up.

Can I delete System Data directly?

No. There is no delete button for it, deliberately, because the files belong to the system and running apps. You can only shrink it indirectly by clearing the things that feed it, like browser caches, messages and pending updates.

Does restarting really reduce it?

Yes, often noticeably. A restart clears temporary files and triggers housekeeping that the phone postpones during normal use. It is the safest first step and takes two minutes.

Will resetting my iPhone fix a huge “Other” category?

A backup, erase and restore is the most thorough fix and usually brings System Data back to a small, healthy size. It is time-consuming, so only use it when the category stays enormous despite every gentler step.