See where your SharePoint storage went.
A free Windows tool that turns the SharePoint Online “storage black box” into a clear, drilldown-able map. Sites, libraries, file types, age, access patterns - all in one place.
Read-only access · No vendor lock-in · Forever free
Sound familiar?
SharePoint Online is a storage black box.
Limited visibility
Microsoft's admin centre only goes so far. You can't see what's actually taking up space inside each library.
Hidden giants
There are huge files in your tenant right now. You don't know which ones. You don't know which sites.
Decision paralysis
Without insights, you can't decide what to archive, delete or migrate. So you do nothing, and the bill keeps growing.
Features
Everything an admin needs. Nothing they don't.
Document Library View
Drill into any SharePoint document library - see storage usage, file composition and access patterns at the library level.
Site-level overview
Bird's-eye view across your whole SharePoint Online environment. Spot rapidly-growing sites before they become storage emergencies.
File browser
Browse, sort and inspect SharePoint files without leaving the tool. Optimised for admins, not casual users.
Top 100 files
Surface the largest files in your tenant in one click. Easy targets for archiving, deletion or relocation.
File-type breakdown
Understand the makeup of your storage - what's PDFs, what's media, what's old Office macros nobody opens.
Light scan or deep scan with file versions
A light scan for a quick baseline, or a deep scan with file versions when you are building a business case.
Comprehensive reporting
Detailed reports across sites, libraries, file counts and inactive content age brackets - board-meeting ready.
Read-only and secure
Operates with read-only access against SharePoint. Your data stays untouched while you analyse it.
Scan modes
Light scan or deep scan with file versions
Two ways to read the tenant. The light scan is the quick baseline; the deep scan with file versions is the only mode that records version counts and version bytes per file.
| Light scan | Deep scan with file versions | |
|---|---|---|
| What it visits | Each site in the tenant, reading the metadata SharePoint exposes at site and library level: site name, library name, total bytes, file count and library type. Individual files are not enumerated. | Every file in every library across the sites you select, with each file's version chain enumerated. |
| What it reports | Site overview and document library view, with a site-level versions storage estimate. | Everything in the light scan, plus the Top 100 files, the file-type breakdown, per-folder sizes in the file browser, and version counts and version bytes per file. |
| Version information | An estimate per site, calculated as storage used minus file sizes. Enough to see whether version history is eating storage, not which files. | Version count and version bytes for every file, so you can sort a library by version count and see exactly which files are carrying the weight. |
| When to use it | A first baseline, a high-level report for management, or finding which sites have grown the most since the last scan. | Identifying specific files for cleanup, precise per-folder sizes before a migration or archive project, or the deeper detail on the sites a light scan flagged. |
| How long it takes | Minutes to hours, depending on the number of sites. The default scope is the 100 largest sites. | Hours to days for a whole tenant. Enumerating versions adds substantially to that on large tenants, so run it on the sites that matter rather than everything at once. |
The documentation recommends skipping file-level versions for a first scan and switching Include file-level versions on once you know which sites deserve the detail.
Reports
What it reports
The views and reports the tool produces, using the names you will see in the interface.
Site overview
Every site in the tenant, largest first: total storage, file count, owner, last modified, growth trend against the previous scan and versions storage.
Document library view
Each library in a site with its type, storage, file count, folder count, largest file, average file size and versions storage.
File browser
A folder tree showing the cumulative size of any folder including its subfolders, and a file table with size, modified, created, version count and path. Export any folder to CSV.
Top 100 files
The largest files in the tenant with site, library, path and who created or last modified them. Needs a deep scan.
File-type breakdown
Per extension: file count, total size, average size and share of tenant storage.
Inactive content report
Files bracketed by last-access age: 30, 90, 180 and 365+ days.
Versions per file
On a deep scan with file versions, version count and version bytes for every file, so you can see how much of a library is version history rather than current documents.
Tenant summary, site-detail and cleanup-targets reports
Pre-built reports as PDF or Word: tenant storage, top sites, growth, file types, largest files and archive candidates. Every view also exports CSV.
Full detail on every view is in the SharePoint Storage Explorer documentation.
Inside the tool
Drill from tenant to a single file.
Document Library View
Per-library breakdowns of storage, file composition and user activity.
File browser
Browse and sort SharePoint files without leaving the tool.
Tenant overview
The strategic dashboard - file types, sizes and distribution across the whole tenant.
Charts and analytics
Top sites by size, top file types by storage - all visual, all interactive.
Compared
How it compares
The question admins actually have is which folders are the biggest offenders and where the storage creep is coming from. The Microsoft 365 admin centre usage report answers neither, and a Get-SPOSite or PnP script answers it slowly.
| SharePoint Storage Explorer | Microsoft 365 admin centre usage report | Get-SPOSite / PnP scripts | |
|---|---|---|---|
| Depth | Tenant, site, library, folder and file. | Tenant and site totals only. | Per site, and only what the script collects. |
| Data freshness | As of the scan you just ran. | 24 to 48-hour lag. | As of the run. |
| Folder and file view | Folder tree with cumulative sizes, file table, Top 100 files. | No folder or file view. | Only if you write and maintain the enumeration. |
| Version breakdown | Site-level estimate on a light scan; version count and bytes per file on a deep scan with file versions. | None. | Per-item enumeration, throttled on large libraries. |
| Large tenants | Light scan for a baseline, deep scan with file versions on the sites that matter. | Totals only, whatever the size. | Per-site loops and throttling; hours to days on large tenants. |
| Upkeep | Install, register the app, scan. | None. | Someone has to maintain the script. |
The admin centre is the right place for the tenant total. Once the question is which sites, which libraries and which folders, and whether version history or stale project files are the cause, a scan answers it without anyone writing or maintaining a script.
Used together
Storage Explorer shows you what's there. Squirrel does something about it.
Most enterprises use SharePoint Storage Explorer during the assessment phase to find the inactive content hogging space, then deploy Squirrel to archive it automatically into Azure Blob Storage. Same visibility, ongoing action - and SharePoint storage costs drop 60-85%.
FAQ
Things people ask.
Is SharePoint Storage Explorer really free?
Does it work on large SharePoint Online tenants?
Is it safe? What permissions does it need?
How does it relate to Squirrel?
Can it find inactive or old files?
Does it show how much space version history takes?
Does the site total include the Preservation Hold Library and the recycle bins?
How long does a scan take?
Find out what's eating your tenant.
Download SharePoint Storage Explorer, point it at your tenant, run a scan. One scan tells you more about your SharePoint storage than the admin centre ever will.
Free download
Get SharePoint Storage Explorer.
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