Microsoft is extending its Microsoft 365 Archive solution to support file-level archiving in SharePoint Online (including OneDrive for Business).
This new capability - currently slated for preview in March 2026 and general availability (GA) by July 2026 - will allow organizations to archive individual files (documents) to low-cost cold storage without taking entire SharePoint sites offline. In this article, we'll look at all currently available information on this feature, including its timeline, technical underpinnings, capabilities, and known limitations.
Feature Overview and Timeline
Microsoft 365 Archive was originally introduced in late 2023 as a SharePoint site-level archiving solution, reaching general availability in May 2024.
It enables administrators to archive entire SharePoint sites to a cold storage tier, preserving their content and metadata while freeing up primary storage and reducing costs.
File-level archiving is a much-anticipated enhancement that provides more granular control: instead of archiving whole sites, organizations will be able to archive individual files (or specific document library items) that are no longer actively used. This is particularly useful for managing inactive or “cold” files (e.g. documents not accessed in years) without disrupting access to the rest of an active site or library.
Development Timeline
According to Microsoft’s roadmap and communications, file-level archiving has been in development since early 2025 (Roadmap ID 477371) and was initially targeted for preview in January 2026.
The schedule was later updated to a March 2026 public preview (Targeted Release) and a broad rollout (GA) by July 2026 for standard multi-tenant environments. This timeline reflects Microsoft’s latest roadmap updates as of February 2026.
Technical Architecture & Storage Tier
Microsoft 365 Archive works by moving SharePoint content into a cold storage tier that is fully integrated within the SharePoint platform. In practice, this means archived data remains in-place in Microsoft 365 (within the SharePoint/OneDrive infrastructure) but is shifted to a low-cost Azure storage tier behind the scenes.
Unlike manual offloading of files to external storage (e.g. copying to Azure Blob storage), Microsoft 365 Archive keeps the content within the Microsoft 365 environment, retaining all security, compliance, and search integration benefits. This design provides several technical advantages.
Cost savings
Archived data is billed at approximately $0.05 per GB per month, roughly a quarter of the cost of standard SharePoint storage (which is ~$0.20 per GB per month).
Organizations only incur archive storage charges when their combined active + archived storage exceeds the normal tenant quota; if total storage used remains within the licensed quota, no additional costs apply for archived content.
Governance remains in place
Because archived files remain within SharePoint/OneDrive (just in a distinct storage tier), you don’t need to manage a separate external archive system. All security, compliance, and search functionalities remain intact in the background. This means metadata, version history, and structure are preserved during archive and restored upon reactivation
Retention Policies & Legal Holds
If a SharePoint file is under a retention policy or eDiscovery hold, those controls remain in effect even after the file is archived. In other words, archiving does not circumvent retention requirements – the content is still preserved for the required duration, just in a different storage tier
eDiscovery & Content Search
Archived content is fully discoverable by admins. SharePoint administrators or compliance officers will be able to search archived files through the SharePoint admin center or Microsoft Purview eDiscovery just as they would search active content. This means that even though end users cannot directly see or open an archived file, an admin can locate it if needed for legal/compliance reasons and choose to reactivate or export it.
Security and permissions remain intact on archived files
When content is reactivated, the same users and groups will have access as before. Archive does not strip away classification labels or audit logs. During the archived period, the content is effectively read-only because it’s not accessible to end-users, but it is kept in a secure state and can still be audited via admin tools.
Speed and efficiency
Archiving via Microsoft 365 Archive is extremely fast – typically completed within minutes, regardless of site or file size. Since the operation is effectively a tier change (not a copy-out), even large SharePoint sites or files can be archived almost instantly.
Notably, Microsoft provides a 7-day “instant restore” window after archiving, during which content can be reactivated immediately (implying the data hasn’t yet been fully moved to the slowest storage tier). After that period, if a file remains archived, reactivation involves a rehydration process taking up to 24 hours to make the file available again, regardless of file size.
User experience
Granular file-level archive button
The new capability will allow users or administrators to archive individual files and folders in SharePoint Online document libraries (including OneDrive) without impacting the rest of the site.
In a live demonstration, Microsoft showed that the process is straightforward: select one or multiple files, click “Archive,” and confirm.
Site members and owners will be able to use the Archive button, as long as they have the ability to update the file in question. This empowers content owners to manage their own storage by archiving obsolete files.
Easy reactivation
To restore a file from archive, it will be as simple as using the Reactivate button in the item's context menu.
Note that the demo also showed regular Delete/Rename/Move/Copy actions as remaining available on archived items.
Search and discoverability
User visibility and search
Files which have been archived will be clearly identified by the archive icon.
When searching, users will be able to select Archive as a specific file type to include or exclude results.
Copilot discoverability
Copilot will not retrieve or surface archived content in its responses.
This “out-of-sight, out-of-mind” behavior ensures that AI and user searches focus on active, up-to-date content, thereby improving the relevance of results and avoiding exposure of stale or sensitive information that has been archived.
Admin controls
File level archiving will initially be made available simply as UI actions which can be taken by users as we've already shown, with admin controls limited to enabling or disabling this functionality at either tenant or site level.
Microsoft plans (currently, the estimate is before end of 2026) to release policy-based actions to automatically archive files, similar to how retention policies work (or possibly integrated into retention policy configuration).
Questions
How can I identify which files could be archived?
The most obvious candidates for archiving are inactive files. According to Microsoft, on average, files which haven't been accessed in more than 2 years have a >95% probably of never being accessed again.
Is M365 archive a substitute for backups?
Microsoft 365 Archive is not a backup solution. Archived files are still only stored within Microsoft’s datacenters (with the same redundancy and backups as any SharePoint data, but not an independent copy you control). Archive is meant for reducing costs and clutter for seldom-used data while keeping it available for compliance. For true backup requirements (protection against accidental deletion or corruption), you should rely on Purview retention, version history, or third-party backup services. Archiving a file will not create a second copy; it simply moves the primary copy to a different tier. Likewise, deleting an archived file (or an archived site) is irreversible (unless you had a backup elsewhere).
How will the preview work?
During the public preview (March 2026), some features may be in beta. For example, the self-service reactivation by end-users might be limited or require certain admin settings. There might also be limitations on the number of files that can be archived at once via the UI, or minor UI polish issues.
Microsoft will likely address feedback from the preview before GA.
