Microsoft Copilot Conversation History: Limits, Retention, and What Gets Deleted

Microsoft Copilot has a history problem that's different from ChatGPT or Claude: it's not just that history is hard to search — it's that history persistence itself is unreliable and poorly documented. Users regularly discover that conversations they expected to find are gone, and Microsoft's documentation on how long Copilot retains history is sparse.

This guide explains what's known about Copilot history retention, why conversations disappear, and what you can do about it.

The two very different versions of Copilot

Microsoft has multiple products under the "Copilot" name that behave quite differently:

Consumer Copilot (copilot.microsoft.com): The free and paid consumer AI assistant. This version has limited history persistence. The conversation interface shows recent sessions, but history is not backed by the same kind of account-level storage as ChatGPT or Claude.

Microsoft 365 Copilot (workplace): Available as an add-on to Microsoft 365 business subscriptions. This version integrates with Microsoft 365 apps (Teams, Outlook, Word, etc.) and is governed by your organisation's Microsoft 365 data retention policies. History from M365 Copilot interactions may be stored in Microsoft's compliance infrastructure.

Copilot in Windows: The built-in Windows AI assistant. Interactions here are further separated from browser-based Copilot history.

Most conversation history complaints apply to the consumer version. Enterprise users in managed Microsoft 365 environments have different (and often more robust) history behaviour governed by their IT administrator's settings.

Consumer Copilot: why history disappears

Consumer Copilot's history persistence is session-based, meaning conversations may not reliably persist across the following events:

Browser cookie clear: If you clear cookies for microsoft.com or copilot.microsoft.com, your conversation history will typically be removed. Unlike ChatGPT and Claude (which store history server-side tied to a login), consumer Copilot history is more tightly coupled to local browser state.

Signing in and out: If you use Copilot without signing in to a Microsoft account, conversations are definitely not retained between sessions. Even with a Microsoft account sign-in, consumer Copilot's server-side history retention is less robust than competing platforms.

Inactivity: There is no published inactivity threshold after which Microsoft clears consumer Copilot history, but user reports suggest history does not persist indefinitely the way ChatGPT's does.

Device changes: Conversations accessed on one device may not appear on another, which suggests the history is more browser-session-coupled than fully account-synced.

Microsoft 365 Copilot history retention (enterprise)

For organisations using Microsoft 365 Copilot as part of a business subscription:

Interaction logs exist. M365 Copilot interactions are typically retained as part of your organisation's Microsoft 365 data. The exact retention period depends on your organisation's retention policies configured in Microsoft Purview.

Admin access. Your organisation's IT or compliance team can access Copilot interaction logs through Microsoft Purview's eDiscovery and compliance tools. Individual users generally can't export this data directly — it's available to compliance administrators.

User-facing history. The conversation history visible to individual M365 Copilot users in the interface is separate from the compliance log. The user-facing history may be limited in the same ways as consumer Copilot history.

How Copilot history compares to other platforms

What to do given these limitations

Don't rely on Copilot history for important conversations. Unlike ChatGPT and Claude where history is reliably persistent, Copilot conversations should be treated as ephemeral unless you take steps to preserve them.

Save important conversations immediately. After any Copilot conversation you'll need to reference, either copy-paste the content into a document or use browser print-to-PDF (Ctrl+P → Save as PDF). Don't assume you'll be able to find it in Copilot's history later.

Use LLMnesia to index Copilot conversations as you have them. LLMnesia builds a local index of your conversations as you browse Copilot at copilot.microsoft.com. The index is stored on your device and remains accessible regardless of what happens to Copilot's server-side history. This is the most sustainable approach to maintaining a searchable archive of your Copilot work.

Sign in to a Microsoft account when using Copilot. Anonymous or guest Copilot sessions have zero persistence. Signing in with a Microsoft account at least gives your history the best chance of persisting within a session.

For enterprise users: Work with your IT administrator to understand your organisation's M365 Copilot retention policies and whether your compliance team can provide historical conversation logs if needed.

Microsoft's history transparency gap

One notable difference between Copilot and its competitors: ChatGPT and Claude both have well-documented history retention policies. OpenAI and Anthropic both publish clear guidance on how long they retain conversations and what their export options are.

Microsoft has not published equivalent documentation for consumer Copilot history retention. This makes it harder for users to make informed decisions about what they can rely on Copilot to retain and what they need to preserve themselves. Until that gap is closed, treating Copilot history as potentially ephemeral is the safe default.