DeepSeek vs Microsoft Copilot
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
An open-source agent harness built on a plugin-first design, run from a local Web UI.
AI tool · Freemium
Microsoft's AI assistant for chat, web-grounded answers and, in Microsoft 365 plans, help inside Word, Excel, PowerPoint and Outlook.
Our verdict
DeepSeek (dsh) is an open-source developer tool for building and extending AI agents with plugins, run locally from the command line and still in developer preview with possible breaking changes. Microsoft Copilot is a general AI assistant for chat and web-grounded answers, and it helps inside Word, Excel, PowerPoint and Outlook on Microsoft 365 plans. They serve different purposes, so the choice depends on whether you are building tools or want a ready-made assistant.
Pick DeepSeek if you are a developer who wants to experiment with an extensible agent harness and are comfortable with Node.js and a local command-line setup.
Pick Microsoft Copilot if you want a ready-to-use AI assistant for everyday questions and already work in Microsoft 365 apps.
| Key difference | DeepSeek | Microsoft Copilot |
|---|---|---|
| Type | Open-source developer tool for building agent harnesses | General AI assistant for chat and web answers |
| Setup | Intermediate; install via package manager, Node.js or pnpm needed | Use in a browser or install an app; no developer setup listed |
| Price | Free and open source under MIT; hosted plans are freemium | Freemium |
| Maturity | Developer preview; breaking changes expected | Finished consumer product; no preview warning in the information provided |
| Best at | Extending through plugins and the Cordis model | Web-grounded answers with citations and Office app help |
Written with AI from both products' catalogue entries · updated 2026-10-29
Who each one is for
Choose DeepSeek if you need…
- Developers who want to experiment with an agent harness they can extend with plugins
- Developers already interested in the Cordis plugin model
- People comfortable running a local dev tool from the command line
- Plugin authors who want to publish to the dsh-plugin topic
Choose Microsoft Copilot if you need…
- Microsoft 365 users
- Web-grounded quick answers
Side-by-side
| DeepSeek | Microsoft Copilot | |
|---|---|---|
| Type | Dev tool | AI assistants · General assistants |
| Price | Free and open source (hosted plans: freemium) | Freemium |
| Licence | MIT | — |
| GitHub stars | 269k | — |
| Setup difficulty | Intermediate | — |
| How you get it | Install with a package manager | — |
| Platforms | Web, iOS, Android, API | Web, Windows, iOS, Android |
| Works with | — | Microsoft 365, Edge |
| Main language | TypeScript | — |
| Last code update | 7 days ago | — |
| Hands-on tested by us | — | Not yet |
| Last checked | — | 2026-10-29 |
What each one is
DeepSeek
DeepSeek Harness (dsh) is an open-source agent harness from DeepSeek AI, built so that nearly every part is a plugin. It runs on Cordis, a plugin framework the README links to, and can be started as a local Web UI. The README describes it as being in developer preview, so the interface and APIs may change.
Microsoft Copilot
Microsoft's AI assistant for chat, web-grounded answers and, in Microsoft 365 plans, help inside Word, Excel, PowerPoint and Outlook. Convenient where your work already happens in Microsoft 365. The consumer and business versions differ significantly, which can be confusing.
Best for
DeepSeek
- Developers who want to experiment with an agent harness they can extend with plugins
- Developers already interested in the Cordis plugin model
- People comfortable running a local dev tool from the command line
- Plugin authors who want to publish to the dsh-plugin topic
Microsoft Copilot
- Microsoft 365 users
- Web-grounded quick answers
Strengths
DeepSeek
- Built on a stated everything-is-a-plugin architecture
- Can be started quickly with a single npx command, per the README
- Documentation, a Discord community and GitHub Discussions are linked from the README
Microsoft Copilot
- Web-grounded chat with citations
- Help inside Office apps on 365 plans
- Image generation
- Voice conversations
Not ideal for
DeepSeek
- Users who need a stable production system, since the README warns of compatibility-breaking changes during developer preview
- Anyone who has not read the SAFETY.md notice, which the README asks users to review before running it
- Non-technical users looking for a finished consumer app; the README assumes Node.js or a repository checkout
Microsoft Copilot
—
Trade-offs
DeepSeek
- The README explicitly says it is in developer preview with breaking changes expected
- The README is truncated and gives limited detail on features and models supported
- Requires understanding of Node.js or pnpm and a local dev workflow
Microsoft Copilot
—
Getting started
DeepSeek
Run from npm
npx @deepseek-ai/dsh webClone the repository
git clone https://github.com/deepseek-ai/deepseek-harness.gitMicrosoft Copilot
Get started on the Microsoft Copilot websiteFrequently asked questions
Should I use DeepSeek or Microsoft Copilot?
DeepSeek (dsh) is an open-source developer tool for building and extending AI agents with plugins, run locally from the command line and still in developer preview with possible breaking changes. Microsoft Copilot is a general AI assistant for chat and web-grounded answers, and it helps inside Word, Excel, PowerPoint and Outlook on Microsoft 365 plans. They serve different purposes, so the choice depends on whether you are building tools or want a ready-made assistant. Pick DeepSeek if you are a developer who wants to experiment with an extensible agent harness and are comfortable with Node.js and a local command-line setup. Pick Microsoft Copilot if you want a ready-to-use AI assistant for everyday questions and already work in Microsoft 365 apps.
What is the difference between DeepSeek and Microsoft Copilot?
DeepSeek: An open-source agent harness built on a plugin-first design, run from a local Web UI. Microsoft Copilot: Microsoft's AI assistant for chat, web-grounded answers and, in Microsoft 365 plans, help inside Word, Excel, PowerPoint and Outlook. DeepSeek suits developers who want to experiment with an agent harness they can extend with plugins, while Microsoft Copilot suits microsoft 365 users.
Are DeepSeek and Microsoft Copilot free?
DeepSeek: Free and open source (hosted plans: freemium). Microsoft Copilot: Freemium.
What are other alternatives to DeepSeek and Microsoft Copilot?
Other options people compare them with include LangChain, CrewAI, Our Free Model, Claude, ChatGPT.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.