Find Out What Is Using Your Storage

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    Settings → General → iPhone Storage

    Wait for the bar chart to load — it takes 10–20 seconds. The coloured bar shows exactly how storage is split: Apps, Photos, Media, Mail, Messages, and System Data. Tap any category for more detail. This is your starting point for knowing where to focus.

Reduce System Data (the Hardest Category)

System Data (formerly “Other”) includes caches, logs, Siri data, streaming buffers and other files iOS manages automatically. You cannot delete it directly, but these steps reduce it significantly:

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    Clear Safari cache

    Settings → Apps → Safari → Clear History and Website Data. This removes browsing history, cookies and cached web content. Can free several hundred MB. You will be signed out of websites.

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    Offload unused apps

    Settings → General → iPhone Storage → Enable Offload Unused Apps. Or manually: tap any app in the list → Offload App. Offloading removes the app but keeps its data — reinstalling restores everything. Offloading streaming apps (Netflix, Spotify, YouTube) removes downloaded content which can be gigabytes.

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    Delete large message attachments

    Settings → General → iPhone Storage → Messages → Review Large Attachments. Sort by size and delete photos and videos sent or received in messages you no longer need. These can accumulate to gigabytes over time.

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    Clear individual app caches

    Many apps accumulate large caches. For apps like Spotify, Podcasts, or Maps: open the app settings within each app and look for a Clear Cache or Delete Downloaded Content option. For any app: delete and reinstall it — this wipes the cache completely.

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    Back up and restore (nuclear option)

    If system data is excessively large (10GB+) and other steps have not helped: back up your iPhone to iCloud or a computer, then erase it (Settings → General → Transfer or Reset iPhone → Erase All Content), and restore from backup. This resets system data to a clean state.

Photos are usually the biggest culpritBefore tackling system storage, check whether Photos is actually your largest category. Enable iCloud Photos (Settings → Photos → iCloud Photos → Optimise iPhone Storage) — this keeps full-resolution photos in iCloud and stores smaller versions on the device, potentially freeing gigabytes immediately.

Frequently Asked Questions

iOS stores caches, logs, Siri voice data, streaming buffers (from Apple Music, Podcasts, Netflix), and temporary files in System Data. It is supposed to manage this automatically, but it can grow unexpectedly if you stream a lot of content, have many apps running, or have not restarted your phone in a long time. Restarting your iPhone monthly helps iOS clear temporary caches. The back up and restore method is the most effective reset if it becomes very large.
Yes — offloading is completely safe. Your app data (save files, settings, login state) is preserved. When you reinstall the app, it picks up exactly where you left off. The only exception is apps that store data locally without iCloud backup — very rare for mainstream apps. Offloading is better than deleting when you want to free space but keep your data.