What Is a SharePoint Archive Site?
A SharePoint archive site is a SharePoint Online site that has been hibernated using Microsoft's own Microsoft 365 Archive feature. Once archived, the site is removed from active navigation and search, its content is moved into a lower-cost archive tier inside Microsoft's cloud, and end-users can no longer access it. Only administrators can see the site is still there, and only administrators can reactivate it - for a per-GB reactivation fee.
The archive-site model is Microsoft's answer to the SharePoint storage cost problem for content that is genuinely finished with. A completed project site, a decommissioned department workspace, a legacy Teams site that nobody has opened in a year - all candidates for being turned into an archive site rather than deleted outright.
This guide explains what a SharePoint archive site actually is, how Microsoft 365 Archive puts a site into that state, what the archive costs and what the reactivation costs, what users and administrators see once a site is archived, and where file-level archiving with a third-party tool like Squirrel fits when the whole-site hibernation model is too coarse.
How Microsoft 365 Archive Turns a Site Into an Archive Site
Microsoft 365 Archive is a paid Microsoft service that operates on SharePoint sites at the site collection level. The mechanics of turning a live site into an archive site:
- Administrator selects the site in the SharePoint admin centre and initiates the archive action. Microsoft 365 Archive must be enabled on the tenant first, which is a paid add-on.
- The site is put into a hibernated state. All content within the site - document libraries, lists, pages, site assets, everything - moves from the standard SharePoint pool tier into Microsoft's archive tier.
- The site disappears from active surfaces. It no longer appears in SharePoint search results, no longer shows up in navigation, no longer appears in the recent-activity feeds users see across Microsoft 365. Direct links to the site or to files within it stop working - users clicking them see the standard "a SharePoint administrator archived this site" warning.
- Storage cost drops from the SharePoint pool tier to the archive tier. Microsoft's published rates are $0.20 per GB per month for standard SharePoint pool storage above the tenant entitlement, versus $0.05 per GB per month for archive-tier storage - a 75% reduction on Microsoft's own published tariff.
- The site remains discoverable to compliance workflows. Microsoft Purview eDiscovery and Content Search can still reach archived content, though export times are longer than for active content. Retention policies continue to apply, and legal holds continue to be enforced.
Reactivating an archive site is a separate administrator action with a separate cost model - covered in the reactivation section below.
What a SharePoint Archive Site Costs
The economics of archive-site hibernation have three components: the ongoing storage cost while archived, the reactivation cost when the site needs to come back, and the practical operational cost of managing the archive lifecycle.
Ongoing storage cost. Content in a SharePoint archive site is billed at $0.05 per GB per month at Microsoft's published rate - a 75% discount on the $0.20 per GB per month standard SharePoint pool overage rate. For a 1 TB site, the archived storage cost is approximately $50 per month, versus $200 per month if that same 1 TB stayed in the standard SharePoint pool as overage.
Reactivation cost. When an archive site needs to be brought back to active use, Microsoft charges a one-off reactivation fee of $0.60 per GB on the content being reactivated. For a 1 TB site, reactivation costs $600. This is the fee that turns the archive-site economics into a genuine trade-off: it only saves money on data that stays archived for a long time. If a site is archived and reactivated frequently, the reactivation fees offset the storage savings quickly.
Re-archive lockout. After reactivation, Microsoft imposes a 120-day lockout during which the site cannot be re-archived. This defeats automated lifecycle patterns where a site is archived, briefly reactivated for an audit, and then re-archived. The lockout was originally 30 days and was extended to 120 days in mid-2026.
Bundled cost. For the full picture of how the archive-site cost sits within the broader SharePoint pool economics - including the base pool entitlement of 1 TB plus 10 GB per user, the overage rate structure, and Microsoft 365 Archive's place in Microsoft's pricing - see SharePoint Online pricing.
What Happens When a SharePoint Site Is Archived
The user experience and administrator experience diverge significantly once a site becomes an archive site.
End-users experience the archived site as inaccessible. They see the standard SharePoint warning message: "This site is archived. A SharePoint administrator archived this site. If you need access, ask an admin to reactivate it." Every navigation link into the site, every shortcut, every direct URL to a document within the site behaves the same way - nothing loads, and the warning message appears instead. Content is completely invisible to SharePoint search, to the Files hub, to the recent-activity feed, and to Microsoft Copilot's grounding pass.
Administrators can see the archive site in the SharePoint admin centre. The site is listed under Sites → Archived sites (or the equivalent view in the tenant's admin centre configuration). Administrators can view metadata about the site - creation date, size, when it was archived, who archived it - but cannot browse the site's content directly without reactivating.
Compliance and legal continue to work. Microsoft Purview eDiscovery, Content Search, retention policies, and legal holds all continue to apply to content in the archive site. Compliance investigators can retrieve archived content through eDiscovery workflows. This is important for regulated industries: an archive site is still a compliant repository, just an inaccessible-to-users one.
Microsoft Copilot is excluded. Content in a SharePoint archive site is explicitly excluded from Microsoft Copilot's grounding, which means Copilot cannot surface archived content in its answers. For enterprises where archived documents may still be relevant to Copilot-driven Q&A workflows, this is one of the biggest limitations of the archive-site model. See Microsoft Copilot and archived SharePoint content for the full behaviour across archive mechanisms.
For step-by-step guidance on reactivating an archive site (both the Microsoft-archived warning scenario and file-level restore scenarios), see how to restore or reactivate an archived SharePoint site.
When a SharePoint Archive Site Is the Right Choice
The archive-site model works well for a specific shape of content: entire sites that are genuinely finished with, that nobody needs to access day-to-day, and where the cost of occasional reactivation is acceptable.
Good fits for the archive-site model:
- Completed project sites where the project is closed, no active work is happening, and reactivation for the occasional audit is acceptable.
- Decommissioned department or team sites where the department no longer exists but the content must be preserved for compliance.
- Historical archives of legacy content that has been superseded by a newer site structure.
- Sites subject to long retention windows where the content is compliance-required for years but is rarely if ever accessed.
Bad fits for the archive-site model:
- Sites where some content is inactive but other content is still in daily use. The archive-site model is site-level - it archives everything or nothing. If a site has 1 TB of stale content and 100 GB of actively-used content, archiving the whole site takes the active 100 GB offline too, breaking user workflows.
- Sites where users need occasional read-only access to old content. The archive-site model is not a read-only tier - it is fully inaccessible until admin reactivation. Users cannot self-serve.
- Sites where Microsoft Copilot grounding is important. Archived content is excluded from Copilot answers by design.
- Environments where frequent archive/reactivate cycles are expected. The 120-day re-archive lockout and $0.60/GB reactivation fee make repeated cycles economically painful.
For the second and third categories in particular, file-level archiving is often a better fit than site-level archiving.
File-Level Alternative: Squirrel
Where Microsoft 365 Archive operates at the site level, Squirrel operates at the file level. Squirrel identifies individual files within a site based on lifecycle policies (last-modified date, last-accessed date, file type, folder path, library, site), moves the file content to customer-owned Azure Blob Storage, and leaves a stub file in the original SharePoint location.
The practical difference for the end-user:
- The site stays fully accessible - the archive-site "administrator archived this site" warning does not appear because the site itself is not archived.
- Individual files that have been archived show up as stubs in the SharePoint library, retaining the original filename, metadata, and modified date. Users can search for the stub and click it to trigger a one-click restore from Azure.
- Restore happens in seconds, not the 24-hour reactivation window Microsoft 365 Archive documents for older archived content.
- No per-restore or reactivation fees - Squirrel's licence covers the full archive-and-restore cycle.
- Content stays discoverable by Microsoft Copilot via the Nutshell AI module, which embeds AI-generated summaries of archived documents into the stub file so Copilot's grounding pass still sees the semantic content.
Squirrel stores archived data in the customer's own Azure subscription, in the customer's chosen region and Azure Blob storage tier (Hot, Cool, Cold, or Archive). Archived data typically costs an order of magnitude less than Microsoft's $0.05/GB/month archive tier because Azure Blob Cool and Archive tiers are priced well below Microsoft's rate.
For the direct feature-by-feature comparison, see Squirrel vs Microsoft 365 Archive in 2026.
SharePoint Archive Site Frequently Asked Questions
How do I archive a SharePoint site?
An administrator archives a SharePoint site by opening the SharePoint admin centre, selecting the site, and initiating the archive action. Microsoft 365 Archive must be enabled on the tenant beforehand as a paid feature. The archive is applied at the site collection level and cannot be applied to individual libraries or files within a site. For the step-by-step operational walkthrough covering both Microsoft's native archive-site model and file-level archive with Squirrel, see how to archive a SharePoint site.
How much does a SharePoint archive site cost?
Microsoft charges $0.05 per GB per month for archived storage - a 75% reduction on the standard $0.20 per GB per month SharePoint pool overage rate. A one-off reactivation fee of $0.60 per GB applies when an archive site is brought back to active use. A 120-day lockout prevents re-archiving after reactivation.
Can users access an archived SharePoint site?
No. Once a site is archived using Microsoft 365 Archive, end-users see the "A SharePoint administrator archived this site" warning message and cannot access any content within the site. Only administrators can see the archived site in the admin centre, and only administrators can trigger reactivation. Microsoft Purview eDiscovery and Content Search can still reach archived content for compliance purposes.
Can I archive individual files instead of the whole site?
Yes, but not with Microsoft 365 Archive's site-level model - that operates on entire sites only. For file-level archiving where individual inactive files move to lower-cost storage while the rest of the site stays active and accessible to users, use a purpose-built file-level archiver like Squirrel. Squirrel leaves a stub file in the SharePoint library so users can still find and one-click restore individual archived files without any administrator involvement.
Does an archived SharePoint site still count against my tenant storage?
Archived content moves from the standard SharePoint pool tier to Microsoft's archive tier, at the reduced $0.05/GB/month rate. The content still exists in Microsoft's cloud - it does not leave your tenant - so it still contributes to your overall Microsoft 365 storage commitment, just at the lower archive-tier rate. If you want archived content to move out of Microsoft's cloud entirely (into your own Azure Blob Storage), that requires a third-party file-level archiver like Squirrel.
Is archived content visible to Microsoft Copilot?
No. Microsoft explicitly excludes content in Microsoft 365 Archive from Copilot grounding. This means Copilot cannot surface archived documents in its answers. For enterprises where archived content should remain discoverable by Copilot, file-level archiving with a solution that preserves Copilot grounding (like Squirrel with the Nutshell AI module) is the appropriate pattern.
How long does it take to reactivate an archived SharePoint site?
Microsoft documents reactivation as taking up to 24 hours. Practical reactivation times vary depending on the site size and Microsoft's current archive tier load. There is also a 120-day lockout after reactivation during which the site cannot be re-archived. Squirrel's file-level restore, by contrast, completes in seconds regardless of how long the file has been archived, with no lockout.
Can I search an archived SharePoint site?
No. Archived sites are removed from the SharePoint search index by design. Search queries do not return results from archived sites, and neither does Microsoft Copilot. For content that must remain searchable while archived, file-level archiving with stub files preserves search discoverability - the stub remains indexed by SharePoint search even after the file content is moved to Azure.
Related Guides on SharePoint Archive Sites
- How to restore or reactivate an archived SharePoint site - both the Microsoft-archived warning scenario and the Squirrel file-level restore workflow.
- How to archive a SharePoint site - step-by-step for both site-level and file-level patterns.
- Squirrel vs Microsoft 365 Archive in 2026 - the head-to-head comparison across lifecycle, coverage, restore speed, Copilot, and storage ownership.
- Microsoft Copilot and archived SharePoint content - the visibility gap that shapes many archive decisions in 2026.
- SharePoint Online pricing - the full cost picture including archive-tier rates, reactivation fees, and pool overage.
Audit Your SharePoint Storage Before Deciding
Before committing to any archive pattern - Microsoft 365 Archive site-level, file-level with a third-party tool, or a mix - it helps to see where your SharePoint pool is currently being consumed. SharePoint Storage Explorer is a free Windows tool that breaks down site, library, and file-type consumption across the tenant in one view. It is the fastest way to identify which sites are genuinely finished with (candidates for archive-site hibernation) versus which sites have inactive files inside otherwise-active workspaces (candidates for file-level archiving).
For the Squirrel deployment story from the file-level side, see the Squirrel product page and how Squirrel stubs work in SharePoint.
