Office for Mac Issues

Fix OneNote for Mac Using Excessive Storage and Slowing Down

Maira Mehtab Oct 10, 2026 869 views

Question details

The user needs to resolve an issue where OneNote is consuming tens of gigabytes of disk space and causing severe system performance drops.

How to Fix OneNote for Mac Using Excessive Storage and Causing Slowdowns

Product: Microsoft OneNote
Device & OS: macOS
Scenario: Managing digital notebooks and syncing files using OneNote on a Mac.
Observed behavior: OneNote becomes extremely slow, freezes while typing, force-quits unexpectedly, overheats the Mac, and uses an abnormally large amount of local storage.

Before you start

Ensure all your OneNote notebooks are fully synchronized to the cloud and resolve any visible sync errors to prevent permanent data loss before clearing local cache files.

Solution 1Recommended

Clear OneNote Local Cache Data

Use this solution to remove bloated temporary files that are consuming gigabytes of storage and causing the app to freeze.

OneNote stores offline copies and temporary cache files for faster loading. Over time, or due to synchronization conflicts, these cache files can grow to an unmanageable size, leading to overheating and application slowdowns.

Verify Notebook Synchronization

Open OneNote and look at the sync status icon next to your notebooks. Right-click each notebook and select 'Sync This Notebook' to ensure all recent changes are uploaded to OneDrive.

Quit the Application

Completely close the app by right-clicking the OneNote icon in the Dock and selecting 'Quit', or by pressing Cmd + Q.

Navigate to the Caches Folder

Open Finder, click 'Go' in the top menu bar, hold down the 'Option' key to reveal the 'Library' folder, and click it. Navigate to Containers > com.microsoft.onenote.mac > Data > Library > Caches.

Delete Cache Contents

Select all files and folders inside the Caches directory and move them to the Trash. Empty the Trash to free up your disk space, then restart OneNote.

Initial Loading Time: After clearing the cache, OneNote will take longer to load initially as it downloads fresh data from your synced cloud notebooks.

Solution 2

Reset OneNote Preferences

Delete the configuration files to fix persistent bugs, freezing, and corrupted application settings.

Solution 3

Reinstall OneNote from the Mac App Store

Perform a clean installation when cache clearing and preference resets fail to resolve the overheating and storage bloat.

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Try WPS Office for a Lightweight Mac Experience

If Microsoft Office applications are consuming too much storage and slowing down your Mac, consider switching to WPS Office. It provides a lightweight, all-in-one suite that handles your document needs efficiently without draining system resources or disk space.

1. Download the Installer: Visit the official WPS Office website and download the free installer for macOS.
2. Install the Application: Open the downloaded file and drag the WPS Office icon into your Applications folder.
3. Start Creating: Launch WPS Office to easily manage your documents, spreadsheets, and presentations in one lightweight interface.

Lightweight installation that saves precious Mac disk spaceFully compatible with Microsoft Office formats (.docx, .xlsx, .pptx)Smooth performance without causing system overheating or freezingBuilt-in cloud synchronization and PDF editing tools

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Frequently Asked Questions

Why is OneNote taking up tens of gigabytes on my Mac?

OneNote locally caches copies of your notebooks, including images, file attachments, and version histories to allow for offline access. If sync conflicts occur or if you have massive notebooks, this local cache can exponentially grow, leading to excessive storage usage.

Will clearing the OneNote cache delete my notes?

Clearing the cache only removes the local temporary files stored on your Mac. As long as you have verified that your notebooks are completely synced to OneDrive beforehand, your actual notes are safe and will re-download when you reopen the app.

How do I check if my OneNote notebooks are fully synced?

Look for the sync status icon (a cloud with a checkmark) near your notebook's name in the sidebar. You can also manually force a sync by right-clicking the notebook and selecting 'Sync This Notebook'. If there is a sync error, a warning icon will appear instead.

What happens when I delete the OneNote preferences file?

Deleting the '.plist' file removes your personalized app configurations, such as custom view settings or toolbars. It forces OneNote to recreate the file with default settings upon the next launch, which often resolves unexpected freezing or slow typing issues.

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