Every Microsoft 365 tenant accumulates SharePoint sites that outlive their purpose. Finding them and deciding what to do is a routine governance task with three realistic approaches - each suited to different team sizes and skill sets.
| Capability | M365 Admin Center | PowerShell / PnP | ShareMaster |
|---|---|---|---|
| Last-activity date per site | Yes | Yes | Via storage report |
| Site owner identification | Basic | Yes | Yes (permission matrix) |
| Library-level drill-down | No | Yes (scripted) | Yes (Report Master) |
| Version and storage breakdown | No | Yes (scripted) | Yes (Report Master) |
| Excel export | CSV only | Custom script required | Yes (built-in) |
| Bulk site deletion | No (one at a time) | Yes (Remove-SPOSite) | Yes (Space Master) |
| No-code / no-script option | Yes | No | Yes |
| Scheduled / automated runs | No | Yes | No (manual) |
| Setup required | None | PowerShell + PnP modules | ShareMaster install |
Option 1: Microsoft 365 Admin Center
The admin center is the zero-setup starting point. Under Reports > Usage > SharePoint > Site usage you get a table of all site collections with their last activity date (page views, file activity), storage consumed, and file count. The reporting window is selectable: 7, 30, 90, or 180 days.
The export button produces a CSV you can open in Excel and sort by the last-activity column. Sites showing no activity in the chosen window are your review candidates.
Where the admin center falls short:
- The report shows site-collection level only. A site with zero file activity might still host active subsites, and a site with page views might hold no useful content. The number alone is rarely conclusive without a follow-up conversation.
- The admin center doesn't show the current site owner in the same report view. Getting owner details requires clicking through to each site, or using PowerShell.
- Site deletion through the admin center UI is one at a time. For a tenant with 30 candidates, that's 30 manual delete operations.
For a quick quarterly check of a small to medium tenant (under 100 sites), the admin center is adequate. It becomes a bottleneck once your candidate list grows past 20-30 sites.
Option 2: PowerShell and PnP PowerShell
PowerShell unlocks automation and precision. The Microsoft SharePoint Online Management Shell and PnP PowerShell both expose site properties including last-modified date, owner account, and storage consumed. A standard workflow looks like this:
- Connect to the tenant admin URL with
Connect-SPOServiceorConnect-PnPOnline. - Pull all sites with
Get-SPOSite -Limit Alland retrieve theLastContentModifiedDateproperty. - Filter to sites where
LastContentModifiedDateis older than your inactivity threshold (90 or 180 days is common). - Export the filtered list to CSV for review, then pass confirmed candidates to
Remove-SPOSite.
PnP PowerShell's Get-PnPTenantSite is often faster for large tenants and returns richer metadata. The -Detailed switch adds storage quota, owner, and site template information in a single call.
Where PowerShell becomes the bottleneck: writing and maintaining scripts requires skills that not every admin team has. On tenants with more than 500 sites, API throttling can make enumeration slow. And bulk deletion through Remove-SPOSite has no visual review step, so one wrong filter condition can remove sites you intended to keep.
PowerShell is the right choice when you have scripting skills in-house and want a scheduled, automated cleanup process. It integrates naturally into broader Microsoft 365 management pipelines via Task Scheduler or Azure Automation.
Option 3: ShareMaster (Report Master and Space Master)
ShareMaster takes a two-tool approach: Report Master handles the discovery phase; Space Master handles the deletion phase.
In the discovery phase, Report Master exports a storage utilisation report across all sites in the tenant. Sites with near-zero storage or zero version counts are strong review candidates, and the permission matrix export from the same tool surfaces which ones lack an active owner - often the most reliable proxy for abandonment. Both outputs land in Excel, ready for stakeholder review without further scripting.
Once candidates are confirmed, Space Master's Bulk Delete Sites lets you select multiple sites from a GUI and remove them in a single operation. No PowerShell required. Deleted sites pass through SharePoint's standard admin recycle bin before permanent removal, giving you a 93-day safety window.
ShareMaster is a Windows desktop application. Both the discovery and deletion steps require running it from a machine with a ShareMaster licence and SharePoint admin (or global admin) credentials. It does not require a server-side deployment or Azure app registration.
Compared to the admin center, you get library-level drill-down and a built-in Excel export with version and storage breakdowns. Over PowerShell, the main gain is a visual review step with no scripting requirement. The trade-off: it's an on-demand process rather than a scheduled automation.
Decision Matrix: Which Option Fits Your Scenario?
| Scenario | Best option | Reason |
|---|---|---|
| Quick snapshot, no tools available | M365 Admin Center | Zero setup, immediate CSV export |
| Tenant with 100+ sites, need owner data at scale | PowerShell / PnP | Single cmdlet call returns full metadata for all sites |
| Non-technical admin, needs Excel output for sign-off | ShareMaster | GUI-based discovery with formatted Excel export, no scripting |
| Bulk deletion without scripting risk | ShareMaster (Space Master) | Visual selection prevents accidental bulk removal of wrong sites |
| Scheduled, automated quarterly cleanup | PowerShell | Scriptable and integrates with Azure Automation or Task Scheduler |
| Permission audit alongside site cleanup | ShareMaster | Permission matrix export identifies ownerless sites in the same workflow |
| Small MSP managing multiple client tenants | ShareMaster | Switch between tenants within one tool without re-scripting per client |
For most teams that run a quarterly governance review, the practical workflow is: use the admin center to get the initial candidate list, confirm owners via PnP PowerShell if needed, and use Space Master to bulk-remove confirmed candidates. All three options play a role at different stages.
Try ShareMaster free for 14 days
Frequently Asked Questions
How do I find inactive SharePoint sites in the admin center?
Go to Reports > Usage > SharePoint > Site usage in the Microsoft 365 admin center. The report shows last activity date per site collection. Export to CSV, open in Excel, and sort by the last-activity column to surface sites with no recent use.
What counts as an inactive SharePoint site?
Microsoft's usage reporting counts a site as active if it had at least one file view, file edit, or page visit in the reporting period (7, 30, 90, or 180 days). In practice, many organisations use 90 days of zero activity as the threshold for a review conversation with the site owner before taking any action.
Can I bulk-delete inactive SharePoint sites without PowerShell?
Yes. ShareMaster's Space Master includes a Bulk Delete Sites tool that lets you select multiple sites from a GUI and remove them in one operation, without writing any scripts. Sites deleted this way pass through the SharePoint admin recycle bin and can be recovered for up to 93 days before permanent removal.
Does deleting an inactive site release storage quota immediately?
No. Deleted sites move to the SharePoint admin recycle bin and continue counting against tenant storage quota for 93 days. The quota doesn't recover until you permanently purge the site from that bin. Factor this delay into storage-reduction planning. See also: how to reduce SharePoint storage fast.