Squirrel vs Microsoft 365 Archive
Updated 15 June 2026 to reflect Microsoft's latest file-level archive doc update, including the change from a 30-day to a 120-day re-archive lockout. File-level archive remains in public preview at the time of writing, with general availability rolling out late June to late July 2026.
Microsoft 365 Archive is Microsoft's native cold-storage feature for SharePoint. The site-level mode (whole-site hibernation) is generally available. The file-level mode is in public preview and rolling to general availability between late June 2026 and late July 2026. Squirrel is a third-party archiver that moves SharePoint content into the customer's own Azure Blob Storage with stub files that work consistently across SharePoint, OneDrive sync, and Microsoft Teams, with scheduled policy automation that Microsoft does not offer at the file level. This post compares the two on the things that actually decide the call: what each can archive, whether policies are automated, how users get their files back, where the data ends up, and which Microsoft 365 surfaces work with archived content.
Both products solve a real problem - SharePoint Online pricing charges $0.20 per GB per month over the entitlement, which gets expensive quickly - but they solve it differently. Microsoft 365 Archive is a storage tier inside Microsoft's cloud, with site-level and (in preview) file-level operations. Squirrel is a policy-driven archive system that writes into Azure storage the customer owns, with stubs designed to work consistently across the SharePoint web UI, OneDrive sync, and Microsoft Teams.
For a comparison against the incumbent enterprise archiver in this space rather than Microsoft's native option, see AvePoint alternative for SharePoint archiving - it covers what AvePoint Opus does, where it stores archived data, and the constraint AvePoint themselves document around active retention policies.
What Microsoft 365 Archive Covers Today
There are now two distinct modes inside Microsoft 365 Archive.
Site-level archive (generally available)
An administrator (or a retention policy) marks a SharePoint site as archived. The site is hibernated and, in Microsoft's own words, "content in this tier is no longer directly accessible to anyone." Site reactivation is administrator-initiated and Microsoft documents it as taking up to 24 hours. The site retains its metadata and permissions, and Microsoft Purview eDiscovery and Content Search can still reach archived content (with longer export times).
File-level archive (public preview, GA late June - late July 2026)
Microsoft announced file-level archive on 30 March 2026 and is rolling to general availability between late June and late July 2026. The operating model is materially different from the site-level mode:
- The archive action is initiated by end users, file by file. There is no policy-driven file archive in the preview or at GA - each file is archived by a user clicking on it.
- A marker is left where the file used to be. End users can click to reactivate.
- For files archived less than 7 days, restore is quick. For files archived 7 days or more, Microsoft documents restore as taking up to 24 hours.
- A reactivated file cannot be archived again for 120 days (Microsoft updated this from 30 to 120 days in June 2026).
- File-level archive is for SharePoint sites only - not OneDrive personal storage.
- Microsoft states that "Copilot is not trained on archived content" - archived files are excluded from Copilot's knowledge.
Microsoft also documents several limitations in the file-level archive preview. Archived files do not behave correctly in Word Online, PowerPoint Online, the Teams, OneDrive, and SharePoint mobile apps, macOS with the OneDrive sync client, older Windows versions (Windows 10 and earlier) with the OneDrive sync client, older Office desktop apps that have not been updated since March 1, 2026, and Clipchamp and Power BI. OneNote files, SharePoint pages, SharePoint agents, and content in the Site Assets library cannot be archived at the file level at all.
Some of these gaps may close as the preview matures, but at GA the coverage profile remains narrower than mature third-party archivers offer in the SharePoint surfaces they support.
Where Squirrel Goes Beyond Microsoft 365 Archive
Five properties carry the comparison.
1. Scheduled, rule-based policy automation. Squirrel archives run on a schedule. Policies can target by last modified date, last accessed date, file type, folder path, library, or whole site - in any combination. Microsoft 365 Archive has no equivalent at the file level: file archive is initiated manually by end users, file by file, in both the public preview and at GA. Site-level archive can be driven by retention policies but only at whole-site granularity.
2. Stubs that work consistently across SharePoint surfaces. Squirrel stubs are visible in the SharePoint web UI, the OneDrive sync client on Windows (current and older) and macOS, and Microsoft Teams (including private channels). Microsoft 365 Archive's file-level marker has documented gaps in macOS OneDrive sync, older Windows OneDrive sync, all three mobile apps, Word Online, PowerPoint Online, Clipchamp, and Power BI.
3. End-user restore in seconds - always. Both Squirrel and M365 Archive file-level support end-user-initiated restore. The difference is timing. Squirrel restores complete in seconds regardless of how long the file has been archived. Microsoft's file-level archive restores quickly for files archived under 7 days but can take up to 24 hours for files archived 7 days or more, with a 120-day lockout before a restored file can be re-archived.
4. Customer-owned Azure storage. Archived data is written into the customer's own Azure Blob Storage account in the customer's own Azure subscription. The customer chooses the region and the access tier (Hot, Cool, Cold, or Archive). M365 Archive keeps content inside Microsoft's cloud at a tier Microsoft sets. If Squirrel is ever removed from the environment, the archived data remains accessible directly in the customer's own Azure storage.
5. Copilot can still see archived content via Nutshell. Microsoft explicitly states that Copilot is "not trained on archived content" - files archived with M365 Archive disappear from Copilot's knowledge. Squirrel can be combined with the Nutshell AI summary feature, which embeds an AI-generated summary of each archived document into the stub. Because the stub is still indexed by SharePoint Search and visible to Copilot, archived content remains discoverable in Copilot answers even after the underlying file has been moved to Azure.
Side-by-Side Comparison
| Capability | Microsoft 365 Archive | Squirrel |
|---|---|---|
| Site-level archive | Generally available | Yes |
| File-level archive | Public preview; GA late June - late July 2026 | Generally available |
| Who initiates file archive | End user, file by file (manual click) | Scheduled policy or end user |
| Lifecycle policy automation | Site-level: retention/inactivity. File-level: none. | Last modified, last accessed, file type, folder path, library, site |
| Marker / stub in SharePoint web | Yes (file-level archive) | Yes |
| OneDrive sync (current Windows) | Yes | Yes |
| OneDrive sync (macOS) | Documented limitation | Yes |
| OneDrive sync (older Windows) | Documented limitation | Yes |
| Microsoft Copilot visibility | Excluded - "Copilot is not trained on archived content" | Discoverable via Nutshell AI summary in stub |
| End-user restore | Yes (file-level) | Yes |
| Restore time | Under 7 days: fast. 7+ days: up to 24 hours. Site reactivation: up to 24 hours. | Seconds |
| Re-archive after restore | 120-day lockout | No lockout |
| Archive scope | Files in SharePoint sites (file-level), whole sites (site-level). Cannot archive OneNote files, SharePoint pages, SharePoint agents, or Site Assets. | Document library content. OneNote, SharePoint pages, and Site Assets are out of scope for both products. |
| Storage location | Inside Microsoft's cloud | Customer's own Azure Blob Storage subscription |
| Storage tier choice | Single archive rate set by Microsoft | Hot, Cool, Cold, or Archive - customer chooses |
| Deployment model | Native Microsoft 365 feature | Managed SaaS; archived data written to the customer's own Azure Blob Storage account |
How Users Actually Restore a File
Microsoft 365 Archive (site-level). An administrator opens the SharePoint Admin Center, locates the archived site, and initiates reactivation. Microsoft documents this as taking up to 24 hours. End users have no direct path - they raise a ticket.
Microsoft 365 Archive (file-level, public preview). The user sees a marker where the file used to be, clicks to reactivate, and waits. For files archived less than 7 days, the file is back quickly. For files archived 7 days or more, Microsoft documents reactivation as taking up to 24 hours. After the file is restored, it cannot be re-archived for 120 days (Microsoft updated this lockout from 30 to 120 days in June 2026). If the user is on macOS, an older Windows version, mobile, Word Online, PowerPoint Online, Clipchamp, or Power BI, the experience may not work as expected - Microsoft has documented these surfaces as having known limitations during the preview.
Squirrel. The user opens SharePoint, OneDrive sync, or Microsoft Teams. The file is right where it was, shown as a stub. Click. Within seconds, the file is rehydrated from the customer's Azure Blob Storage and opens normally. No 7-day threshold, no 24-hour worst case, no 120-day re-archive lockout. The same restore button is available from the SharePoint command bar to rehydrate an entire folder or library in one action.
Lifecycle Policies
Microsoft 365 Archive policy support depends on the mode:
- Site-level archive can be driven by retention policies or administrator action. Granularity is limited to whole sites.
- File-level archive, in public preview and at GA, is manual end-user action only. There is no policy that says "archive files older than X days" or "archive files of these types." Each file is archived by a user clicking on it.
Squirrel policies are rule-based and combinable, running on a schedule:
- Archive files in this library that have not been modified in 365 days.
- Archive files of these types (PSD, MOV, DWG, ZIP) regardless of age.
- Archive everything in this folder path.
- Archive files in this site that have not been accessed in 180 days.
The result is an automated archive pipeline that does not require administrator click-through or user click-through per file or per site.
Where the Data Ends Up
This is the data-ownership question that often decides the call for enterprises in regulated sectors.
Microsoft 365 Archive keeps archived content inside Microsoft's cloud, in the same multi-tenant infrastructure as the active workload, billed at the archive rate. Microsoft controls the region (it follows the SharePoint tenant), the storage tier, and the keys.
Squirrel writes archived content into the customer's own Azure Blob Storage account in the customer's own Azure subscription. The customer chooses the region. The customer chooses the access tier - Hot for actively-restored content, Cool or Cold for typical archive workloads, Archive for long compliance retention. The customer can apply their own Azure-level controls (immutable storage, lifecycle management, network restrictions) on top. There is no SmiKar-hosted copy of customer content. Squirrel is delivered as a managed SaaS - the archived data is written directly to the customer's own Azure Blob Storage account in their tenant.
If Squirrel is ever removed from the environment, the archived data remains in the customer's own Azure storage, accessible directly through standard Azure tools.
Which to Choose
| Scenario | Best fit |
|---|---|
| You need scheduled, rule-based archive policies | Squirrel |
| You need archive coverage across SharePoint web, OneDrive sync, and Microsoft Teams | Squirrel |
| You need archived content discoverable by Microsoft Copilot | Squirrel (via Nutshell) |
| You need restores to complete in seconds, not "up to 24 hours" | Squirrel |
| You need archived data in your own Azure subscription | Squirrel |
| You only need to hibernate occasional inactive sites at a reduced rate | Microsoft 365 Archive |
| You want a native Microsoft 365 feature with no third-party deployment | Microsoft 365 Archive |
| Your users mostly archive their own files individually in modern desktop apps | Microsoft 365 Archive (file-level GA) |
For most enterprises managing SharePoint storage at scale, the deciding factors are policy automation, surface coverage, restore speed, Copilot visibility, and data ownership - which is why Squirrel is the more common choice in that segment.
Frequently Asked Questions
Does Microsoft 365 Archive now support file-level archive? Yes, in public preview. Microsoft announced file-level archive on 30 March 2026 and is rolling general availability between late June 2026 and late July 2026. File-level archive lets end users manually archive individual files in SharePoint sites and click to restore them. There is no policy-driven file archive - each file is archived by a user clicking on it. Several Microsoft 365 surfaces (Office Online, mobile apps, macOS OneDrive sync, older Windows OneDrive sync) have documented limitations during the preview.
How long does Microsoft 365 Archive take to restore? For site-level archive, Microsoft documents reactivation as taking up to 24 hours. For file-level archive, files archived less than 7 days are restored quickly, while files archived 7 days or more can take up to 24 hours. A reactivated file cannot be archived again for 120 days (Microsoft updated this from 30 to 120 days in June 2026). Squirrel restores are initiated by end users from SharePoint, OneDrive sync, or Microsoft Teams and complete in seconds regardless of how long the file has been archived.
Does Microsoft 365 Archive work with Microsoft Copilot? No. Microsoft states that "Copilot is not trained on archived content." Once content is archived with Microsoft 365 Archive, it is excluded from Copilot's knowledge. Squirrel combined with Nutshell AI embeds an AI summary of each archived document into the SharePoint stub, so archived content remains discoverable by Copilot and SharePoint Search even when the underlying file has been moved to Azure. The full explainer with both failure modes (M365 Archive's deliberate exclusion and standard HSM archiving's index removal) is in Microsoft Copilot and archived SharePoint content: the visibility gap.
Which Microsoft 365 surfaces does Squirrel work in? Squirrel's stub files appear in the SharePoint web UI, the OneDrive sync client on Windows (current and older) and macOS, and Microsoft Teams (including private channels). Squirrel does not place stubs in Office Online (Word Online, PowerPoint Online, Excel Online) or Office desktop apps - users access and restore archived files through the SharePoint or OneDrive sync surfaces where the stub is visible.
Can OneNote files, SharePoint pages, and Site Assets be archived? With Microsoft 365 Archive's file-level mode, no - Microsoft documents these as unsupported. Squirrel is also document-library-focused and does not archive OneNote notebooks, SharePoint pages, SharePoint agents, or Site Assets. For these content types, both products leave them in their original location.
Where is the archived data physically stored with Squirrel? In the customer's own Azure Blob Storage account, in the customer's own Azure subscription, in the region the customer chooses. There is no SmiKar-hosted copy of the data.
Does Squirrel encrypt archived content? Yes. Content is encrypted and compressed before being written to Azure Blob Storage. SmiKar holds the encryption keys for archive operations and provides each customer with a copy of their keys for independent access.
Can users archive files themselves, or only administrators? Both. Squirrel runs scheduled policies set by administrators, and also exposes an archive button in SharePoint and Teams that end users can use to archive their own content.
What happens if we stop using Squirrel? The archived data remains in the customer's own Azure Blob Storage account and is accessible directly through standard Azure tools. There is no vendor lock-in on the storage layer.
Does Squirrel affect SharePoint search? No. Stub files remain in SharePoint and are indexed by SharePoint search, so archived content continues to appear in search results.
Related reading
- SharePoint Online archiving - the complete enterprise guide
- SharePoint document lifecycle
- How to archive a complete SharePoint Online site with Squirrel
- Restore an archived SharePoint site
- OneDrive quota enforcement July 2026 (MC1310684)
- Exchange Online Archiving: what it is and what it does not cover
See Real Customer Outcomes
Three Squirrel customers across petabyte enterprise, FTSE 250 industrial, and mid-market financial services have eliminated over $2.1 million per year in Microsoft 365 storage overage between them. Read the customer case study compilation - including a Fortune 500 healthcare brand with a 1.4+ PB SharePoint estate, a FTSE 250 engineering group whose tenant went from 460 TB to 165 TB, and a mid-market firm using Squirrel during a planned file-server migration to SharePoint Online.
