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DeepSeek vs Microsoft Copilot is a choice between a free chatbot with open weights and an assistant sold inside Microsoft 365. Unlike Copilot, DeepSeek’s app costs nothing and has no paid tier. Copilot’s free app, however, shows ads, and its paid version starts at $9.99 a month with Word, Excel and Outlook included.
The bigger split is data. DeepSeek’s privacy policy says it stores personal data in China, while Microsoft is a US company. This page covers Microsoft Copilot, the assistant in Windows and Office, not GitHub Copilot, the coding tool. Overall, our reviews score Microsoft Copilot 3.3 and DeepSeek 3.0.
DeepSeek vs Microsoft Copilot: The Short Answer
Choose Microsoft Copilot for Office work and for anything you would not want stored abroad. Choose DeepSeek instead for free, low-stakes chat, a cheap API or open weights you can run yourself. Copilot also brings models from OpenAI and Anthropic, while DeepSeek runs only its own.
On accuracy, no study has tested both. The EBU and BBC checked Copilot’s news answers in 2025 but not DeepSeek’s. Artificial Analysis, in contrast, tests DeepSeek’s models but not Copilot as a product. So any claim that one is more accurate than the other goes beyond the evidence.
Head to Head
| Criterion | DeepSeek | Microsoft Copilot |
|---|---|---|
| Free app | Yes; no targeted ads, per its policy | Yes; ads without Microsoft 365 |
| Cheapest paid plan | None; API only | Microsoft 365 Personal $9.99/mo, with Office |
| Models | Its own V4.1 Flash and V4 Pro | OpenAI’s and Anthropic’s |
| Inside Office apps | No | Word, Excel, Outlook and more |
| Open weights | V4.1 Flash, downloadable | No |
| Where data is stored | People’s Republic of China | Microsoft, a US company |
| Training on app chats | Yes, unless you opt out | Older app: yes unless you opt out |
| Our score | 3.0 | 3.3 |
Prices and Plans
DeepSeek’s app on the web, iOS and Android is free, and there is no paid consumer tier. Paid use goes through its API instead. V4.1 Flash costs $0.15 per million input tokens and $0.60 per million output tokens off-peak, while V4 Pro costs $0.66 and $1.98.
Microsoft sells Copilot inside Microsoft 365. Personal costs $9.99 a month or $99.99 a year, and Family $12.99 or $129.99, though only the subscription owner gets the AI. Premium costs $19.99 or $199.99, while Microsoft 365 Pro costs $99.99 a month. Our breakdown of what AI tools cost per year puts those figures next to the other assistants.
Models and Features
Copilot runs other companies’ models. In September, Microsoft’s Copilot blog announced Anthropic’s Claude Opus 5.5 and OpenAI’s GPT-6 Sol for Word, Excel and PowerPoint, WindowsForum reported. Our comparison of Claude vs Microsoft Copilot covers using Claude directly versus inside Office.
DeepSeek, in contrast, runs its own models. Its API news page says V4 Pro is available in the app through Expert Mode. The newest model, V4.1 Flash, came out on September 10, 2026. DeepSeek has named a V4.1 Pro but given no date.
For research, Microsoft retired Deep Research in the consumer Copilot app on August 18, 2026. Its successor, Researcher, needs Microsoft 365 Premium or Pro, according to Microsoft’s support page. Meanwhile, we found no comparable cited-report mode documented for DeepSeek’s app.
What the Independent Tests Show
Each tool has been tested, but never against the other. In the EBU and BBC study of October 2025, 37% of Copilot’s news answers had at least one significant issue. Also, 15% had significant sourcing problems. However, DeepSeek was not part of that study.
Artificial Analysis, meanwhile, gives DeepSeek V4.1 Flash 39 on its Intelligence Index. However, on its knowledge test the model declined only 4% of the questions it could not answer, for an AA-Omniscience index of minus 5.3. In addition, on Arena’s text board of September 30, 2026, deepseek-v4.1-flash-max placed 40th of 410.
⚠️ Copilot has no product-level entry on those boards, because it runs other companies’ models. Instead, the scores of those models appear in our Microsoft Copilot review and in the reviews it links to.
Ads, Training and Data
DeepSeek stores your data in China. Its privacy policy, updated on February 10, 2026, says it keeps chat data for as long as the account exists. It may also share that data with authorities under legal process. It trains on inputs unless you turn off Improve the model for everyone. Its policy also rules out targeted advertising.
Copilot’s free app, in contrast, shows ads without a Microsoft 365 subscription. Moreover, personalized ads can draw on chat history and memories, according to Microsoft’s privacy controls page of September 17, 2026. The older app’s FAQ says Copilot trains on chats unless you opt out, while the updated app’s pages list no training switch.
Microsoft says it does not train on Copilot use inside the Microsoft 365 apps on Personal and Family. In addition, Copilot shares chats with Bing, Edge and MSN through One shared experience unless you turn it off.
⚠️ Several governments restrict DeepSeek. Italy blocked the app in January 2025, Australia banned it from government devices, and the Czech Republic barred its public administration, Reuters reported. Check your employer’s rules before using it for work.
Office Work and Coding
For documents and email, Copilot works inside Word, Excel and Outlook, as our guide to Microsoft Copilot for productivity explains. DeepSeek has no Office integration, so you copy text in and out of its chat.
For coding, DeepSeek offers a cheap API and open weights. Its V4 Pro scored 43.1 on Artificial Analysis’s Coding Agent Index when run inside Codex, as mirrored by BenchLM. Our guide to DeepSeek for coding covers that setup. Microsoft’s coding assistant, meanwhile, is GitHub Copilot, a separate product with its own plans.
Who Owns Each
Microsoft Corporation is publicly traded. It also owns about 27% of OpenAI, TechCrunch reported in July, and it committed up to $5 billion to Anthropic in November 2025. DeepSeek’s privacy policy, on the other hand, names Hangzhou DeepSeek Artificial Intelligence Co., Ltd., registered in China, as the data controller.
Where Each One Is Weakest
DeepSeek is weakest on data and on admitting what it does not know. Chats are stored in China, several governments restrict the app, and its newest model rarely declines a question it cannot answer.
Microsoft Copilot is weakest on data clarity and on free use. The updated app’s training rules are unclear, the free app’s ads can use your chat history, and cited research reports need Premium.
Winners by Category
DeepSeek wins on price, because the app is free with no paid tier. It also wins on ads, since its policy rules out targeted advertising, and on open weights and API cost. Microsoft Copilot, however, wins on Office integration and on model choice, with OpenAI and Anthropic models. It also wins on research reports, through Researcher on Premium and Pro.
Copilot also takes data location and workplace use. DeepSeek, on the other hand, takes the training opt-out, with a documented switch where Copilot’s updated app lists none. On accuracy there is no verdict, because no study tested both. Overall, our score favors Microsoft Copilot, 3.3 against 3.0.
When to Choose Each
Take Microsoft Copilot when you already pay for Microsoft 365, work in Office documents or need a tool your employer will approve. Also, on the free app, turn off ad personalization and One shared experience under Personalization.
Take DeepSeek instead for free, low-stakes chat, a low-cost API or self-hosted open weights. Then keep personal and work data out of the app. For other matchups, see our pages on ChatGPT vs Microsoft Copilot, ChatGPT vs DeepSeek, Grok vs Microsoft Copilot and Gemini vs DeepSeek.
How We Research
This DeepSeek vs Microsoft Copilot comparison reuses the sources behind our DeepSeek review and our Microsoft Copilot review, rechecked on October 2, 2026. They include DeepSeek’s privacy policy and API docs, and Microsoft’s plan and privacy pages.
Test results come from the EBU and BBC study of October 2025, Artificial Analysis and Arena, each dated where used. Both scores come from the same five criteria, applied in each tool’s review. Since we run no tests of our own, our about page sets out the criteria behind both scores.
DeepSeek vs Microsoft Copilot FAQ
Microsoft Copilot scores 3.3 in our reviews and DeepSeek 3.0. Copilot fits Office users and workplaces; DeepSeek fits free, low-stakes use, cheap API work and self-hosting.
Yes. DeepSeek’s app is free on the web, iOS and Android, with no paid consumer tier. Paid use goes through its API, from $0.15 per million input tokens off-peak.
The Copilot app is free but shows ads without a Microsoft 365 subscription. Paid use comes with Microsoft 365, from $9.99 a month for Personal.
In the People’s Republic of China, according to its privacy policy. It keeps chat data while the account exists and lets you opt out of training.
No study has tested both. The EBU and BBC found significant issues in 37% of Copilot’s news answers, and Artificial Analysis found DeepSeek V4.1 Flash rarely admits not knowing.
The Verdict
DeepSeek vs Microsoft Copilot goes to Copilot on our score, 3.3 to 3.0, and on anything involving work or private data. After all, it sits inside the Office apps, runs models from two leading labs and keeps data with a US company.
Still, DeepSeek wins on price and openness: a free app without targeted ads, a cheap API and weights you can host yourself. So use it for low-stakes questions and code, and keep sensitive material elsewhere.