DB Labs
What Counts as "Other" in iPhone Storage?
"Other" (renamed "System Data" in iOS 15+) includes Safari cache, Siri voices, system logs, Mail attachments, Spotlight indexes, and streaming caches from apps like Spotify and Netflix. It typically uses 5-15 GB and can't be directly deleted.
What's Included in "Other" / System Data
The "Other" category is a catch-all for data that doesn't fit into Apple's main storage categories (Apps, Photos, Media, Mail, Messages). Specifically, it contains:
- Safari browsing cache — website data, history, cookies, and cached images
- Siri voices and dictation data — downloaded language models
- System logs and diagnostics — crash reports, analytics data
- Mail attachment previews — cached versions of email attachments
- Spotlight search index — the database that powers on-device search
- Streaming caches — buffered content from Spotify, Netflix, YouTube, Apple Music, and Podcasts
- Font files and keyboard data — especially if you use third-party keyboards
- Software update remnants — partially downloaded or leftover iOS update files
Why It Grows Over Time
System Data tends to grow the longer you use your iPhone without restoring it. Every app you use generates cached data, every website you visit adds to Safari's cache, and every streaming session leaves behind buffered content. iOS is supposed to automatically manage this data and trim it when space runs low, but in practice it often doesn't shrink fast enough. Devices that haven't been restarted in weeks tend to accumulate more System Data than those restarted regularly.
How to Reduce It
- Clear Safari data — Settings > Safari > Clear History and Website Data (can free 1-3 GB)
- Restart your iPhone — flushes temporary caches and can reclaim 1-2 GB
- Delete and reinstall large apps — this clears an app's internal cache that "Clear Cache" often misses
- Update iOS — new versions sometimes fix cache management bugs
- Back up and restore — as a last resort, back up via iCloud or Mac, then erase and restore. This rebuilds System Data from scratch and typically reclaims 5-10 GB
When to Worry
System Data under 15 GB is normal. If it exceeds 20 GB, something may be wrong — a streaming app might be caching excessively, or a failed iOS update could be stuck in storage. Check Settings > General > iPhone Storage for a detailed breakdown. If System Data is over 25 GB and nothing else explains it, a backup-and-restore is usually the most effective fix.
Related Articles
- What Is "Other" Storage on iPhone? Full Breakdown
- Glossary: Other Storage on iPhone
- Clear iPhone Cache Without Deleting Photos
- How to Check iPhone Storage Breakdown
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