How to reduce SharePoint storage

First, find out where your storage is going

Before deleting anything, get the numbers. Microsoft's admin reports will tell you which sites are biggest, and that is where their help ends. They show totals per site, not which files are waste: they cannot tell you that the same deck lives on five sites, that a library's real footprint is mostly version history, or that nobody has opened a folder since 2021.

The question that actually reduces storage is not "which site is big?" but "which files can safely go?". That requires a file-level inventory across the whole tenant, with last-accessed dates, duplicates matched by content, and a cost attached to each finding. That inventory is exactly what a TerraBytes scan produces, priced in euros and CO₂ per finding, so your work list writes itself.

Trim version history

SharePoint keeps major versions of every file by default, often up to 500 of them. A frequently edited 20 MB deck that has been saved 200 times can occupy several gigabytes on its own, even though only the latest version matters to anyone.

The catch is that version bloat is invisible: every file list shows you the current file's size, while the versions pile up behind it, and tightening the limits going forward does nothing about the history you already have. TerraBytes measures the true footprint including version history, so you can see exactly which libraries and files carry the bloat, and how much space trimming them would actually give back. In most tenants this is the single biggest win, which is why it belongs at the top of a prioritized cleanup, not at the bottom of a to-do list.

Empty the two-stage recycle bin

Deleting a file in SharePoint does not immediately free storage. Deleted items pass through two recycle-bin stages and can count against your quota for up to 93 days. It is the classic reason cleanups "don't work": you delete for an afternoon and the storage graph barely moves.

Emptying bins is the easy part, and it is permanent, which is exactly why it should come last. The real work happens before that: knowing with confidence what was safe to delete in the first place. TerraBytes attaches a clear recommendation to every finding (keep, archive or delete) and documents the reasoning, so when you do clear the bins you know precisely what went and why, and the reclaimed space actually lands.

Find and remove duplicate files

Duplicates are one of the most common causes of SharePoint bloat. The same policy PDF gets uploaded to five team sites; "Budget_final_v2 (copy).xlsx" lives beside "Budget_final.xlsx"; email attachments get saved again and again. None of it adds value, all of it costs storage.

Manually, you can sort a library by name or size and eye-ball obvious repeats, but that does not scale past one library, and it misses identical files saved under different names. TerraBytes recognizes true duplicates by their content, whatever they are called and wherever they live, and groups them across your whole tenant with the reclaimable space per group. Collapsing each group to a single copy is one of the safest, fastest wins in any cleanup: nobody misses a duplicate of a duplicate.

Archive old and orphaned sites

Every project spins up a site; few are ever cleaned up. Over time you accumulate sites nobody owns, sites untouched for years, and workspaces for initiatives that ended long ago. This is textbook ROT data: redundant, obsolete and trivial.

The tell-tale signals are age and ownership: content untouched for a year or more, with no one left who feels responsible for it. TerraBytes surfaces exactly that, stale files and libraries ranked by last-accessed age and the storage they hold, so archiving stops being a judgement call over thousands of unknowns and becomes a short, documented list of decisions. Every keep-archive-delete choice is recorded, which keeps the cleanup defensible for security and compliance.

Deal with ex-employee OneDrive accounts

When someone leaves, their OneDrive is supposed to be retained briefly and then expire. In practice the retention gets extended "just in case", nobody ever reviews it, and the accounts pile up, each one full storage you keep paying for, holding files nobody can vouch for.

The blocker is never deleting the account; it is knowing what is inside. TerraBytes shows you what each orphaned account actually holds, what is duplicated elsewhere, what has long gone stale, and what contains personal or sensitive data, so you can reassign the few files that matter and confidently let the rest go.

One caution before you start deleting anywhere: much of this data may fall under retention policies, legal holds or GDPR obligations, and ex-employee files in particular often contain personal data. A cleanup that is documented and rule-driven protects you on both fronts: it neither removes what you were required to keep, nor keeps what you were required to delete.

Do it automatically with TerraBytes

Every step above works, but done by hand across a real tenant it is slow, easy to get wrong, and hard to prove afterwards. TerraBytes runs the whole analysis in one pass: a serverless scan that never moves your files and keeps your data encrypted inside your own environment. In a single scan it flags duplicate, outdated, oversized and risky files across SharePoint and OneDrive, ranks them by the storage, euro and CO2 they cost you, and hands you a prioritized action plan. Nothing is deleted automatically: you define the keep, archive and delete rules and stay fully in control. When you are ready to stop guessing where your storage went, see the SharePoint storage cleanup tool.