# Microsoft 365 Copilot vs Glean: which do AI models recommend for Enterprise AI, October 2026

IT AI Recommendation Index, October 2026 Edition, Enterprise AI assistants. Four of fourteen models named Microsoft 365 Copilot first on the direct prompt; one named Glean. Page: https://it-ai-index.com/it-data/enterprise-ai-assistants/microsoft-365-copilot-vs-glean/

| | First-choice share | Rank | Negative rate | Labels | Models naming it |
|---|---|---|---|---|---|
| Microsoft 365 Copilot | 25% | #2 of 7 | 20% | 40 | 14 of 14 |
| Glean | 6% | #5 of 7 | 6% | 16 | 7 of 14 |

## The direct prompt, model by model

- Gemini 3.5 Flash: both first (first choices: Glean, Microsoft 365 Copilot) (alternatives: 1mind, ChatGPT Team or Enterprise, Moveworks)
- DeepSeek V4 Flash: microsoft 365 copilot first (first choices: Microsoft 365 Copilot) (alternatives: ChatGPT, Claude, Glean Assistant, Google Gemini)
- Kimi K2: microsoft 365 copilot first (first choices: Microsoft 365 Copilot) (alternatives: Gong)
- GLM 4.7 FlashX: microsoft 365 copilot first (first choices: Microsoft 365 Copilot) (alternatives: Gong, HubSpot Breeze AI, Monday CRM with AI)
- Perplexity Sonar: neither first, one named (first choices: HubSpot with Breeze AI) (alternatives: Artisan, Glean, Microsoft 365 Copilot, Regie.ai, Writer, ZoomInfo)
- Grok 4.1 Fast: neither first, one named (first choices: Microsoft Copilot) (alternatives: Glean, Gong, Salesforce Einstein)
- GPT-6 Luna: neither first, one named (first choices: ChatGPT) (alternatives: Google Workspace with Gemini, Microsoft 365 Copilot)
- Claude Haiku 4.5: neither named (first choices: 1mind, AI Hive) (alternatives: Gong, Microsoft Copilot)
- GPT-5.4 mini: neither named (first choices: ChatGPT) (alternatives: Gemini for Workspace, Google Gemini, Microsoft Copilot)
- Mistral Small: neither named (first choices: Gong) (alternatives: ChatGPT, HubSpot AI, Monday.com Revenue AI OS)
- Llama 4 Maverick: neither named
- Qwen 3.7 Flash: neither named (first choices: HubSpot Breeze AI) (alternatives: Apollo, Chorus, Clay, Gong, Microsoft Copilot, Salesforce Einstein, Slack AI)
- MiniMax M2.5: neither named
- Muse Glimmer 30B: neither named (first choices: HubSpot Breeze AI) (alternatives: Gong Revenue AI OS, Intercom, Respond.io)

## What the models said about Microsoft 365 Copilot

- "Multiple controversies—EchoLeak (CVE-2025-32711) enabled zero-click data extraction via email injections; summarized confidential emails ignoring DLP/sensitivity labels." (Grok 4.1 Fast, negative prompt, hard negative)
- "Microsoft 365 Copilot was exploited via a zero‑click prompt injection in email (CVE‑2025‑32711), exfiltrating data from OneDrive/SharePoint/Teams without user action." (GLM 4.7 FlashX, negative prompt, hard negative)
- "Do not deploy M365 Copilot unless you have spent months cleaning up internal file-sharing permissions" (Gemini 3.5 Flash, negative prompt, hard negative)
- "If an organization uses Windows and O365 exclusively, Copilot is the default choice due to seamless access to SharePoint documents without leaving the app." (Qwen 3.7 Flash, comparative prompt, first choice)
- "my default recommendation would be Microsoft 365 Copilot if your employees already live in Microsoft 365 and Teams" (GPT-5.4 mini, paraphrase prompt, first choice)
- "My default recommendation: choose Microsoft 365 Copilot if your company already runs on Microsoft 365" (GPT-6 Luna, paraphrase prompt, first choice)

## What the models said about Glean

- "Avoid over-investing in "enterprise-only" platforms like Glean or Moveworks" (Kimi K2, paraphrase prompt, soft negative)
- "Best Overall for Connected Knowledge & Search: Glean ... Glean is the gold standard." (Gemini 3.5 Flash, paraphrase prompt, first choice)
- "Glean: Best for Cross-Platform Knowledge & "Universal Search"" (Gemini 3.5 Flash, direct prompt, first choice)
- "Top Recommendation: Glean" (DeepSeek V4 Flash, paraphrase prompt, first choice)

Share is the count of first choices across the direct, paraphrase, budget and scale prompts over all fourteen models, for a mid-market B2B company; rank is within the category. Comparisons are drawn for the top eight products in each category. Published under CC BY 4.0; the output is the models' output, and nothing here is a recommendation by the index.