How to Reduce SharePoint Online Storage (2026 Guide)

How to Reduce SharePoint Online Storage

Every SharePoint Online tenant gets a base storage pool of 1 TB plus 10 GB per licensed user. Once you exceed it, Microsoft charges $0.20 per GB per month for additional storage - which works out to $2,400 per TB per year, billed on top of your per-user licences. For a tenant carrying tens of terabytes of content, storage quickly becomes one of the larger lines in the Microsoft 365 bill.

The good news is that most SharePoint tenants are carrying far more than they need. Version history, recycle bins, retention copies, and years of inactive files silently inflate the pool. This guide covers the levers that actually move the number, ordered from the quickest wins to the durable fix - all verified against Microsoft's current documentation.

For the wider context on how SharePoint storage is priced and where the pool comes from, see SharePoint Online licensing and pricing and every SharePoint Online limit in 2026.

Where SharePoint Storage Actually Goes

Before deleting anything, it helps to know what consumes the pool. The usual culprits, in rough order of impact:

1. Version history. Every version of every file is stored in full and counts against your quota. A 10 MB file edited 50 times can consume around 500 MB on its own. Across a large tenant, version history is frequently the single biggest consumer of storage.
2. Inactive files. Documents that have not been touched in years still sit in premium SharePoint storage at the full rate.
3. The Preservation Hold Library. When a retention policy is in place, deleting a file does not free space - a copy is written to a hidden Preservation Hold Library and continues to count against your quota.
4. Recycle bins. Deleted files remain in the two-stage recycle bin for up to 93 days, still consuming storage the whole time.
5. Large redundant files. Media, design files, ISOs, and old migration dumps that never needed to live in SharePoint.

The rest of this guide works through each of these.

1. Trim Version History (Usually the Biggest Win)

Because every version is stored at full size, version history is where the largest, fastest reductions usually come from. Microsoft now defaults new document libraries to Automatic version limits (also called intelligent versioning), which thins out older versions over time and can reduce version storage by around 94-96% over six months compared with fixed count limits.

The important catch: changing a version limit only affects new versions. It does not retroactively delete the existing version history already consuming your quota. To reclaim that space you must run a trimming job against existing content.

This is the highest-value cleanup for most tenants, and it has enough moving parts - the automatic algorithm, the PowerShell trimming jobs, the "run a What-If analysis first" warning - that it deserves its own walkthrough. See SharePoint version history storage: find and reduce it for the full method, including the exact New-SPOSiteFileVersionBatchDeleteJob commands.

2. Empty the Recycle Bins

Deleted content is not gone. It moves through a two-stage recycle bin - first the site recycle bin, then the site collection (second-stage) recycle bin - and continues to count against your storage quota for the full 93-day retention window before it is purged automatically.

If you have just deleted a large volume of content and need the space back sooner, an administrator can empty both stages manually. Be deliberate about it: once purged from the second-stage recycle bin, files are gone. The full process, including PowerShell, is in SharePoint Recycle Bin: how to recover deleted files.

3. Clear the Preservation Hold Library Trap

If your organisation applies retention policies or labels, deleting or editing a file does not reclaim space. Microsoft writes a copy of the affected content to the Preservation Hold Library, a hidden library that counts against your tenant quota. On tenants with broad retention policies, this library can grow into terabytes without anyone noticing.

You cannot simply delete Preservation Hold Library content - it is protected by the retention policy by design. Managing it means understanding which policies are driving the growth and whether the retention period genuinely needs to be that long. See the SharePoint Preservation Hold Library storage trap and how to replace it for the options.

4. Find and Clean Your Largest Sites

You cannot reduce what you cannot see. Before a broad cleanup, identify which sites and libraries are actually consuming the pool - the distribution is almost always heavily skewed toward a handful of sites. The SharePoint admin center Active sites view lets you sort every site by storage used, and PowerShell (Get-SPOSite) can rank the whole tenant in one command.

The step-by-step methods - Active sites, the per-site Storage Metrics page, PowerShell, and the admin usage reports - are covered in how to find your largest SharePoint sites. Our free SharePoint Storage Explorer also visualises where storage is being consumed across your tenant.

5. Remove Large Redundant Files

Once you know where the weight is, the manual sweep is straightforward: media libraries, old project archives, design source files, ISO images, and one-off migration dumps that never needed to be in SharePoint. Moving these out of active document libraries frees premium storage immediately. The question is only where they should go instead - which is the difference between a one-time cleanup and a lasting reduction.

The Durable Fix: Archive Inactive Content to Azure

Manual cleanup buys back space, but a growing tenant fills it again. Version history rebuilds, new inactive files accumulate, and within a year or two the storage bar is back in the red. The durable answer is to stop paying the SharePoint rate for content that is no longer active.

SharePoint archiving moves inactive documents out of the SharePoint storage pool into lower-cost storage while keeping them accessible. Squirrel does this on a scheduled, policy-driven basis and writes the archived data into your own Azure Blob Storage account, in your own Azure subscription, at the access tier you choose (Hot, Cool, Cold, or Archive). A lightweight stub stays in SharePoint so users still see and restore their files, and because you own the storage there is no lock-in.

The economics are the point. SharePoint overage costs $2,400 per TB per year. The equivalent data in Azure archive tiers costs a fraction of that, and it is data your organisation owns and controls. For a tenant carrying tens of terabytes of inactive content, that is the difference between a recurring five- or six-figure overage bill and a small Azure line item.

Squirrel can also be paired with Nutshell AI so that archived content stays discoverable by Microsoft Copilot and SharePoint Search, and it archives across SharePoint, OneDrive sync, and Microsoft Teams. For a full comparison with Microsoft's native option, see Microsoft 365 Archive vs Squirrel.

A Practical Order of Operations

For most tenants, the sequence that reclaims the most space with the least risk is:

1. Identify your largest sites and libraries so you know where to focus.
2. Trim existing version history - usually the single biggest reduction.
3. Empty recycle bins if you need recently deleted space back immediately.
4. Review Preservation Hold Library growth and the retention policies driving it.
5. Sweep out large redundant files.
6. Put a scheduled archiving policy in place so inactive content stops accumulating in the pool.

Steps 1 to 5 are one-time cleanups. Step 6 is what keeps the storage bar out of the red for good.

Frequently Asked Questions

Why is my SharePoint storage full even after deleting files? Deleting files does not immediately free space. Deleted content sits in the two-stage recycle bin for up to 93 days, and if a retention policy applies, a copy is also written to the Preservation Hold Library, which counts against your quota. Version history of existing files also continues to consume storage regardless of deletions.

What is the fastest way to reduce SharePoint storage? For most tenants, trimming existing version history reclaims the most space fastest, because every version is stored in full. After that, emptying recycle bins and reviewing the Preservation Hold Library are the next quickest wins. See SharePoint version history storage for the exact steps.

How much does extra SharePoint storage cost? Microsoft charges $0.20 per GB per month for storage above your pooled allocation of 1 TB plus 10 GB per licensed user. That is $2,400 per TB per year, on top of your per-user licences.

Does archiving reduce SharePoint storage? Yes. Archiving moves inactive files out of the SharePoint storage pool into lower-cost storage. With Squirrel, archived data is written to your own Azure Blob Storage at a fraction of the SharePoint overage rate, while a stub keeps the file visible and restorable in SharePoint.

Related reading

• SharePoint version history storage: find and reduce it
• How to find your largest SharePoint sites
• SharePoint Recycle Bin: how to recover deleted files
• SharePoint Preservation Hold Library explained
• SharePoint Online archiving - the complete enterprise guide
• Every SharePoint Online limit in 2026

Stop Paying the Overage Bill

If your SharePoint storage bar is in the red, cleanup buys you time - archiving buys you a durable fix. See how Squirrel cuts SharePoint storage costs by moving inactive content into your own Azure storage, or contact us to talk through your tenant.