Semantic Index Rollout and Timing

Overview

Copilot doesn’t magically know about your organization’s content. It finds information through the Semantic Index—an enhanced understanding layer built on top of Microsoft Graph and SharePoint search. If content isn’t indexed, Copilot can’t find it.

This video explains what the Semantic Index is, how it’s built, what timing to expect, and how to monitor progress so you can set realistic expectations with your users.

What You’ll Learn

• What It Is: The Semantic Index as an understanding layer beyond keyword search
• How It’s Built: User-level and tenant-level indexing processes
• Timing: When to expect the index to be ready and what affects speed
• Monitoring: How to check indexing health and troubleshoot gaps

Script

Hook: Copilot is only as good as its index

When a user asks Copilot to find a document, summarize a project, or pull information from across the organization, Copilot needs to know where that content is and what it means. That’s the Semantic Index.

If content isn’t in the index, Copilot can’t find it. If the index is incomplete, Copilot’s responses will be incomplete. Understanding how the index works and when it’s ready is essential for managing expectations during your deployment.

What the Semantic Index is

The Semantic Index for Copilot is an enhanced understanding layer built on top of Microsoft Graph.

Microsoft Graph is the data fabric that connects your Microsoft 365 environment—users, files, emails, meetings, chats, sites. It knows what content exists and who has access to it. The Semantic Index adds a deeper layer: it understands what that content is about, how it relates to other content, and how people interact with it.

Traditional search is keyword-based. You search for “quarterly budget” and get documents that contain those words. The Semantic Index goes further. It understands that a document titled “Q3 Financial Review” is related to budgeting even if it doesn’t contain the word “budget.” It maps relationships between content, people, and activities to enable the kind of natural language interactions that Copilot provides.

Here’s the good news for admins: the Semantic Index is built automatically. You don’t need to configure it manually, create mappings, or tag content. When Copilot is enabled in your tenant, the Semantic Index begins building based on the content that already exists in your Microsoft 365 environment.

It respects your existing permissions model. The index doesn’t create new access paths. It organizes and understands content within the same permission boundaries that already govern your SharePoint sites, OneDrive files, Exchange mailboxes, and Teams conversations.

How the index is built

The Semantic Index is built in two layers.

The user-level index covers each individual user’s content—their emails, their OneDrive files, their Teams chats, their calendar. This index is personal to each user and powers Copilot’s ability to answer questions like “What did I discuss with Sarah last week?” or “Find the document I was working on yesterday.”

The user-level index starts building when a user is assigned a Copilot license. It processes the user’s recent activity and content first, then works backward through older content. The more a user interacts with Microsoft 365, the richer their personal index becomes.

The tenant-level index covers shared organizational content—SharePoint sites, Teams channels, shared mailboxes, and any content that multiple users can access. This is what powers Copilot’s ability to answer broader questions like “What is our organization’s travel policy?” or “Find the latest project status report.”

The tenant-level index is built from your SharePoint search index. If content is searchable in SharePoint, it’s available for the Semantic Index to process. If a site is excluded from search or has indexing issues, that content won’t be available to Copilot.

Both indexes update incrementally. When new content is created or existing content is modified, the index updates to reflect those changes. This isn’t instantaneous—there’s a processing delay—but it means the index stays current without any manual intervention.

Throughout the entire process, permissions are enforced. The Semantic Index never surfaces content to a user who doesn’t have permission to access it. The understanding layer operates within the same security boundary as every other Microsoft 365 service.

Timing expectations

Here’s what to expect for timing, which is the most common question admins ask.

The user-level index is typically available within a few days of license assignment. For most users, Copilot starts being useful for personal content queries within 24 to 72 hours. Recent content is indexed first, so users will notice that Copilot can find emails from this week before it can find documents from six months ago.

The tenant-level index takes longer, especially for organizations with large SharePoint environments. For tenants with hundreds of sites and millions of documents, the initial indexing pass may take several weeks to complete. The Semantic Index processes content in the background, and the speed depends on the volume and complexity of your content.

In government environments, the indexing process works the same way as in commercial. The timing expectations are consistent—there’s no additional delay specific to GCC, GCC High, or DoD beyond what any tenant of similar size would experience.

What affects indexing speed? Content volume is the primary factor. A tenant with 10 SharePoint sites will index much faster than one with 500. Site complexity matters too—sites with deeply nested folder structures or complex permission inheritance take longer. And tenant size overall influences the processing queue.

Don’t expect everything to be indexed on day one. Plan your pilot timing to allow at least one to two weeks after license assignment before evaluating Copilot’s ability to find organizational content. This gives the Semantic Index time to build a meaningful foundation.

Monitoring and troubleshooting

There’s no dedicated “Semantic Index status” dashboard—at least not yet. But there are ways to monitor progress.

SharePoint search health is your best proxy. The Semantic Index builds on the SharePoint search index, so if search is healthy, the Semantic Index has a good foundation. In the SharePoint admin center, check the search health reports. Look for crawl errors, sites that aren’t being indexed, and content that’s excluded from search results.

Copilot response quality is a practical indicator. Have your pilot users ask Copilot to find specific organizational content that you know exists on SharePoint. If Copilot finds it, the index is working for that content. If it doesn’t, investigate whether the content is searchable in SharePoint directly.

Common issues that affect the Semantic Index include sites excluded from search—check your search configuration for excluded URLs or paths. Search disabled at the site level—some SharePoint sites have search turned off, which means their content won’t be in the index. And stale content—if content hasn’t been crawled recently, the index may be outdated. Force a recrawl of important sites if needed.

If you’ve verified that SharePoint search is healthy, content is accessible, and permissions are correct, but Copilot still can’t find content that it should, contact Microsoft support. Provide specific examples of content that Copilot should find but doesn’t, along with the site URLs and user accounts involved.

Close: setting user expectations

The most important thing you can do as an admin is set the right expectations with your users.

Tell them Copilot gets smarter over time. In the first few days, Copilot may not find everything they’re looking for. It might miss documents that exist but haven’t been fully indexed yet. It might give incomplete answers about organizational topics because it hasn’t processed all the relevant content.

This is normal. The Semantic Index is building, and quality improves as it matures. By the second or third week, users will notice that Copilot’s responses are richer, more complete, and more relevant.

The key message for users: give it time, keep using it, and the experience will improve. The Semantic Index learns from your organization’s content patterns—the more content it processes, the better Copilot becomes at understanding and surfacing what matters.

Sources & References

• Semantic Index for Copilot — Primary documentation for the Semantic Index
• Microsoft 365 Copilot setup — Setup guidance including indexing considerations
• Microsoft 365 Copilot requirements — Requirements that affect indexing behavior