Why is the OneDrive app taking up so much space on my iPhone?

Turner Faye 0 Reputation points
2026-08-19T17:46:21.61+00:00

The OneDrive app on my iPhone 11 is using about 16 GB of storage, even though I do not have any files set for offline use. I have already tried offloading and reinstalling the app, but the storage usage remains unchanged. I also cannot find a cache-clearing option in the app. On my Android device, the same OneDrive account only uses around 1 GB of storage. Why is OneDrive using so much storage on my iPhone, and how can I free up the space?

Microsoft 365 and Office | OneDrive | For business | iOS
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  1. Lin v 1,295 Reputation points Independent Advisor
    2026-08-19T18:55:27.12+00:00

    Hi‌ Turner,

    OneDrive can store cached content such as file previews, thumbnails, temporary files, and recently accessed files on the device. As a result, storage usage on iPhone can be significantly higher than on Android, even when the same OneDrive account is being used and no files are marked for offline access.

    Since you've already confirmed that no files are marked for offline use and have already performed the documented Offload App and reinstall steps, the next checks would be:

    • Verify that no additional OneDrive accounts have offline content stored locally.
    • Completely delete and reinstall the OneDrive app to ensure any remaining local app data is removed.

    If storage usage remains around 16 GB after these steps, the issue may be related to retained iOS app data or a OneDrive for iOS caching issue rather than actual offline files. At that point, I would recommend having your IT administrator open a support case with Microsoft. Microsoft's support team can perform a deeper investigation and help determine the cause of the unexpected storage usage on the OneDrive for iOS app.

    In case you do not know who your IT admin is, kindly refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support.

    I hope your issue gets resolved soon. If you have any further questions or updates, please don’t hesitate to share.

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  2. AI answer

    2026-08-19T17:46:41.24+00:00

    On iPhone, OneDrive can use a large amount of local storage even when no files are marked offline because the app stores local app data such as previews, temporary files, and cached content for performance. iOS also handles app storage differently from Android, which is why the same account can appear much smaller on Android.

    Since offloading and reinstalling did not reduce the storage, the remaining space is likely app data that iOS kept or content associated with OneDrive on the device.

    Steps to check and reduce the space used:

    1. Check whether any files or folders are still stored locally.
      • In the OneDrive app, review Offline Files.
      • Also review whether more than one account is signed in, because another account may have offline content stored locally.
    2. If the app is taking up a lot of space on the device, use iPhone storage offload.
      • Open Settings on iOS.
      • Go to General > iPhone storage.
      • Select OneDrive.
      • Select Offload App.
      • This removes the app but keeps its documents and data.
    3. Reinstall OneDrive after offloading.
      • After reinstall, Camera Upload and Organize new uploads may need to be set up again.
    4. If files were marked offline previously, remove them.
      • In OneDrive, select the offline file or folder and tap Remove from Offline.
    5. If the issue is tied to sync or app state, reset the app.
      • In OneDrive for iOS, go to Profile > Settings > Account.
      • Select the account if more than one is configured.
      • Select Reset.

    Important limitation:

    • The documented iOS offload flow keeps documents and data, so it may not fully clear all locally retained OneDrive data.
    • The provided support content does not document a general cache-clear option for OneDrive on iOS.

    If OneDrive storage itself is full, that can also affect uploads and sync, but it does not explain iPhone app storage by itself. OneDrive storage includes OneDrive files and anything in the OneDrive Recycle Bin.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

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