OneDrive Taking Up Too Much Space On Mac

Question

OneDrive Taking Up Too Much Space On Mac

Amy Morway 20

Hello everyone!

My OneDrive is taking up way too much space on my Mac, up to 600GB+, even though I have it set to "Download Files As You Use Them" under OneDrive preferences. This problem shows up in my Mac storage under "System Data" in the gray bar, which is constantly calculating.

Any recommendations on how to fix this issue and keep it fixed?

Thank you so much!

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Answer 1

Anonymous

Hi Amy Morway

Thank you for reaching out to Microsoft Q&A Forum and sharing your issue.

Based on Microsoft support documentation and macOS troubleshooting best practices, this behavior is not a bug but a result of how macOS categorizes storage. Files synced through OneDrive are stored in the ~/Library/CloudStorage/OneDrive directory, and macOS classifies all content in the Library folder as "System Data" (reflected in the gray bar that continuously recalculates). Consequently, even with Files On-Demand active, any locally downloaded files (such as those accessed for previews or thumbnails) will contribute to this category rather than appearing as distinct OneDrive storage.

You may consider trying these recommended troubleshooting steps:

Use “Free Up Space” on Files: This is the most direct way to reclaim disk space. For detailed guidance, refer to: Save disk space with OneDrive Files On-Demand for Mac - Microsoft Support
Adjust sync settings: In OneDrive preferences, go to Account > Choose Folders and uncheck anything you don’t need stored locally. This prevents them from being downloaded in the future.
Pause and Resume Sync to Address Caching Issues: Temporary sync glitches can lead to excessive caching. From the OneDrive menu bar icon, select Help & Settings > Pause syncing (for at least 2 hours). After a brief wait, resume syncing. Then, verify your storage via Apple menu > About This Mac > Storage > Manage...
Perform a OneDrive Reset: If issues persist, resetting the application can clear accumulated caches while preserving your cloud files (which will resync). Follow the instructions here: Reset OneDrive - Microsoft Support
Empty OneDrive Recycle Bin: Deleted files still take up space until permanently removed.
Minimize Use of "Always Keep on This Device": Reserve this setting for essential offline files only, as it enforces full local downloads and exacerbates System Data growth.

I hope this explanation clarifies the situation and one of these steps helps you resolve the issue. Please let me know how you get on, as your feedback is valuable to the community.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Amy Morway 20 Reputation points

2025-09-24T19:29:13.66+00:00

Hello Flora-T!

Thank you so much for this explanation and these ideas! I will try these out and let you know how it goes!
Anonymous

2025-09-26T15:06:22.07+00:00

Hi Amy Morway

It has been a while since your last approach. I have not heard anything from your end.

Could you tell me if you have any news from you?

I'm looking forward to seeing your response soon.
Amy Morway 20 Reputation points

2025-09-29T11:30:08.5233333+00:00

Hello Flora-T!

I thank you very much for following up!

For #1, I did not try to use Files On-Demand because I already have everything synced to NOT be stored locally, so there should be no files on my computer until I download them. Although we still have this problem, it is clear that something from OneDrive is being stored locally.

I followed your directions for #2-#6, but unfortunately, nothing has changed. System data is still calculating and taking up more than 700GB of space now.

I reset OneDrive, but I am waiting to hear back from my boss for a code to sign back in. Perhaps something will change once I sign back in?

If you have any other thoughts, I'd love to hear!

P.S. I do have a file that shows how my disc space is sorted, if you would like to see that.
Anonymous

2025-09-29T14:49:45.33+00:00

Hi Amy Morway

Thank you for the detailed update.

On step 1: I get that your setup is already geared toward cloud-only storage with Files On-Demand, so local files shouldn't be an issue unless something's being cached behind the scenes. It could still be worth a quick check by right-clicking a folder or two in your OneDrive view in Finder and selecting "Free up space" to rule out any overlooked items. If that doesn't seem relevant or help, that's fine; we can skip ahead.

As for the reset: You're spot on that signing back in might be the key, since it lets OneDrive fully resync and potentially clear out those stubborn caches. Once you get the code from your boss and log in, give it some time to settle and check the Storage Management screen again. If things don't improve after that, we may need a stronger approach.

In that case, you may consider trying a full uninstall and reinstall of OneDrive to address any potential app bugs or compatibility glitches.
Amy Morway 20 Reputation points

2025-09-30T11:13:10.7766667+00:00

Hello Flora-T!

I heard back from my boss and received a new password so I could log back in to OneDrive! While I was logged out, hundreds of GBs were restored to my Mac storage! Hooray! However, once I logged back on, they all came back, and now my Mac's storage is fuller than it was before.

I followed your advice and right-clicked the main folders in my OneDrive to "Free Up Space" for ha-ha's, but no change.

So we may need to fully uninstall and reinstall the program! Is there any danger of losing files?

Thank you!
Anonymous

2025-09-30T14:37:50.99+00:00

Hi Amy Morway

Thanks for the quick update.

A full uninstall and reinstall does seem like the next logical step and there's no real risk, since your files are safely stored in the OneDrive cloud, not just locally. For extra reassurance, you need to take a look at them through the web version before you start.

If my response was helpful, even in part, I’d be grateful if you could mark my initial answer as Accepted. It helps other affected users find this thread more easily and acknowledges the support you received.

I truly appreciate your time and contribution.
Amy Morway 20 Reputation points

2025-10-02T10:53:24.5966667+00:00

Thank you, Flora-T! I just accepted your first answer!

Do you have a link for a step-by-step process for uninstalling and reinstalling?
Anonymous

2025-10-02T14:35:13.36+00:00

Hi Amy Morway

Thank you for your reply.

Please refer to this Microsoft official article for a step-by-step guide for uninstalling and reinstalling OneDrive on your Mac: Reinstall OneDrive - Microsoft Support

Hope this helps clarify the situation and gives you a path forward.
Amy Morway 20 Reputation points

2025-10-02T15:00:45.7566667+00:00

Hello Flora-T!

I just uninstalled the OneDrive by putting it into the trash on my computer! I also deleted a file that was full of the content that my company has on the OneDrive. That folder did the trick, and a bunch of GBs were removed from my Mac's storage.

I'm having trouble reinstalling, though. When I go to the website you sent me to reinstall the app, it downloads onto my Mac, but when I click on it to "Setup", it says "the application can't be opened" with the code -10661. Any thoughts on this?
Anonymous

2025-10-03T11:51:40.2166667+00:00

Hi Amy Morway

Thanks for the update.

You're encountering error code -10661 when attempting to reinstall OneDrive on your Mac. This typically indicates that the application you're trying to open is either in an incorrect format or not executable on macOS.

Based on my testing, the file should end in .pkg, not .exe

To reinstall OneDrive properly, please use the official Microsoft link for Mac and ensure you're using the correct installer format: Download OneDrive for Mac

Also, note that both OneDrive and macOS receive frequent updates. For compatibility and release information, you can refer to: OneDrive Release Notes for macOS
Amy Morway 20 Reputation points

2025-10-06T19:30:19.9433333+00:00

Hello Flora-T!

It looks like we have reached the end of an epic saga!

Your final help and expertise did the trick, and I now have my OneDrive back on my Mac, as well as all the storage back! Thank you so much! If it happens again, I shall consult this list of fixes once again.

I appreciate you very much!