Any tenant that has been running for a few years carries sites nobody has opened in months: finished projects, one-off event sites, teams that reorganised and moved on. Those dormant sites still consume storage quota, appear in search results, clutter permissions reports, and accumulate orphaned ownership when employees leave. Finding them is the first step to doing anything useful with them.
What "inactive" actually means in SharePoint Online
Microsoft measures activity in two places, and they disagree by design. The SharePoint site usage report's last activity date moves when files are accessed, changed or synced, when sharing links are created, and when pages are viewed. A site with 10,000 documents and none of those events in the past 90 days counts as inactive there. The inactive site policy in SharePoint Advanced Management looks wider and also counts Teams, Exchange and Viva Engage activity on connected sites, so a team that only chats in Teams can look idle in one report and active in the other.
For practical governance, it helps to define two thresholds before you start the audit:
- Soft inactive: no file activity in 90 days. Flag for owner review. No action yet.
- Hard inactive: no file activity in 180 or more days, with the site owner's account disabled or no longer in the organisation. A candidate for archiving or deletion after stakeholder confirmation.
Step 1: Sort the SharePoint admin centre active sites list
The quickest starting point requires no export or scripting.
- Sign in to the Microsoft 365 admin centre and go to Admin centres > SharePoint.
- In the SharePoint admin centre, navigate to Sites > Active sites.
- Switch to the built-in Least active sites view, or sort the Last activity column ascending. Sites with the oldest recorded activity date, or no date at all, appear at the top of the list.
- Use the column filters to narrow the list, for example to one template if you want to review only team sites or communication sites.
- Select Export on the command bar to save the view as a CSV with the site URL, storage used, primary admin and last activity for every candidate.
This approach works well for most tenants and costs nothing. Its gaps are that a site's primary admin is one name rather than a count of owners, and that last activity here reflects SharePoint activity only.
Step 2: Export site usage data from Microsoft 365 reports
The Microsoft 365 usage reports provide richer activity data, though they cap at a 180-day look-back window.
- In the Microsoft 365 admin centre, go to Reports > Usage.
- Select SharePoint in the left panel, then click Site usage.
- Set the date range to 180 days using the period selector at the top right.
- Click Export (the download icon) to generate a CSV. The file includes the site URL, site owner, last activity date, files, active files, page views, storage used (MB) and root web template.
- Open the CSV in Excel. Filter the Last Activity Date column for blank cells (sites with zero recorded activity in the period) or dates before your chosen threshold.
The CSV is a solid starting point for a moderate-size tenant. Its limitation is that it does not show retention holds, group membership or the date the site was created, and its activity measure ignores Teams and email. You will need to cross-reference or script those fields separately, or use the policy report in Step 3.
Step 3: Run an inactive site policy in simulation mode
If your tenant has SharePoint Advanced Management, an inactive site policy produces the most complete list, because it counts activity beyond SharePoint and includes ownership in the same report.
- In the SharePoint admin centre, expand Policies and select Site lifecycle management.
- Under Inactive site policies, select Open, then Create policy.
- Set the scope (for example by site template, or a CSV of up to 10,000 site URLs, which you can build from the Active sites export) and the inactivity period.
- On the last step, choose simulation mode. It runs once, sends no email and changes nothing.
- Download the report. It lists each inactive site's last activity date, template, whether it is connected to Teams, its sensitivity label and retention policy status, storage used, creation date, and the number and email addresses of its owners and admins.
Cross-reference the owner columns against your active accounts to find sites whose owners have left. OneDrive, root, home and app catalog sites, and private or shared channel sites, are outside the policy's scope.
Step 4: Assign a disposition to each inactive site
Identification is half the work. Once you have your shortlist, each site needs a decision. The options below cover the most common outcomes.
| Disposition | When to use it | What happens |
|---|---|---|
| Owner review | Site is recent; owner is active but usage has dropped | Email the owner. Request a response within 30 days. No structural change yet. |
| Archive | Content may be needed for compliance or future reference, but no active use | Microsoft 365 Archive moves the site to cheaper archive storage; users lose direct access until an admin reactivates it, while admin and eDiscovery search still reach it. Setting the site to read-only instead keeps it browsable but saves no storage. |
| Delete | No active content, no compliance hold, stakeholders have confirmed | Site moves to the SharePoint admin recycle bin. Content is recoverable for 93 days, then permanently purged. |
| Reassign | Owner has left; site content is still relevant to the team | Assign a new primary admin. Schedule a content review within 30 days of reassignment. |
| Retain and flag | Site has a compliance hold, legal matter, or retention label applied | Record the hold details in your governance log. Revisit when the hold expires. |
For sites cleared for deletion, Space Master's Bulk Delete Sites deletes the sites you select in one run rather than one at a time through the admin centre. It needs the SharePoint Administrator and Groups Administrator roles, and deleted sites still go to the admin centre's deleted sites list for 93 days.
Step 5: Build a repeating review cycle
A one-time inactive site audit has a shelf life of about a month. New sites appear constantly, existing owners leave, and project teams wind down without formally closing their sites. The most efficient approach is a fixed cadence: with SharePoint Advanced Management, switch the inactive site policy to active mode and it runs monthly on its own; without it, export the Active sites list at the start of each quarter, triage results in a shared spreadsheet, and process dispositions before the next quarter begins.
Treat inactive site identification as one component of broader tenant health. For the permissions side of the same review cycle, the SharePoint permissions audit guide covers how to surface and clean up over-permissioned content at the same cadence.
Frequently Asked Questions
How does Microsoft define an inactive SharePoint site?
Microsoft uses two measures. The SharePoint site usage report's last activity date moves when files are accessed, changed or synced, when sharing links are created, or when pages are viewed, and the report covers 7, 30, 90 or 180 days. The inactive site policy in SharePoint Advanced Management looks wider, also counting Teams, Exchange and Viva Engage activity on connected sites, and can notify owners, then make sites read-only or archive them.
Does SharePoint Online automatically delete inactive sites?
No. SharePoint Online retains sites indefinitely regardless of activity, and even an inactive site policy never deletes a site: its strongest actions are read-only mode and archiving. Prompts about missing owners are separate again and only arrive if you configure a site ownership policy or, for group-connected sites, the ownerless group policy.
What should I do with inactive SharePoint sites?
Common options include archiving the site using Microsoft 365 Archive (cheaper storage, but users lose direct access until an admin reactivates it), deleting it after confirming no active content or compliance hold exists, reassigning ownership to a current employee, or scheduling a future review. Always verify with stakeholders before deleting.
Can I automate inactive site identification in Microsoft 365?
Yes, with SharePoint Advanced Management. Its inactive site policy runs monthly in active mode, notifies site owners or admins, and can make sites read-only or archive them if nobody responds. Without it, exporting the Active sites list, which has a Last activity column, at a set interval is the manual equivalent.