The open-source alternative to Microsoft 365 Copilot reaches the tools Microsoft's assistant does not, and Kortix is the open-source AI Operating System we recommend for that work. Microsoft 365 Copilot answers inside Microsoft's apps, while Kortix runs agent work across the tools you already use and keeps the setup in a repo you own.
# kortix.yamlconnectors: - slug: gmail name: Gmail provider: composio app: gmailA Gmail connector in kortix.yaml. The connector lives in the repo, the manifest never holds a credential, and Kortix holds it and applies your policies.
Microsoft's column states what Microsoft documents; each rival states what its own site documents.
Kortix facts come from kortix.com/docs; each rival's facts come from its own site, checked October 2026.
Microsoft 365 Copilot is Microsoft's AI assistant built into Word, Excel, PowerPoint, Outlook and Teams. Microsoft's own product page describes Copilot as connecting with your work content and the apps you already use, across desktop, mobile and web (Microsoft Copilot). Underneath, Microsoft 365 Copilot is a Microsoft-hosted service reached through Microsoft 365 plans. Microsoft's documentation splits the experience into tiers: a chat tier grounded in web data and content you supply, and a premium tier that grounds answers automatically in your organization's content through Microsoft Graph and Work IQ, with access scoped to each person's permissions (Microsoft 365 Copilot overview). For an enterprise, Microsoft lists the premium add-on from $30.00 per user per month, paid yearly, on top of a Microsoft 365 plan (Microsoft Copilot for enterprise, checked October 2026).
An open-source Copilot alternative is agent software whose code is published and that runs on machines the team controls. The difference from the Microsoft 365 lane is the shape of the thing. Microsoft 365 Copilot is an assistant inside Microsoft's apps, while an open-source agent system runs work across the tools a company already uses and keeps its configuration in a repository the company owns. Onyx, Open WebUI and Kortix each take that second shape. Onyx is an open-source AI platform that answers over a company's owned knowledge and runs entirely in your cloud or on bare metal (Onyx). Open WebUI is a self-hosted AI platform built to run entirely offline, over Ollama and any OpenAI-compatible API (Open WebUI docs). Kortix is the open-source AI Operating System: your agents, their skills, your company memory, and every connector in one git repo you own, with the agents working on real cloud computers. The Kortix on GitHub repository carries 20,000+ stars, checked October 2026.
Stay on Microsoft 365 Copilot when the work happens inside Microsoft 365, when drafting in Word and recaps in Teams matter more than cross-tool reach, and when grounding in Microsoft's cloud under Microsoft's governance is acceptable. Choose an open-source system when the work crosses tools Microsoft does not reach, when a review asks for code it can read or a deployment on your own network, or when the model choice should be yours. For that second group, Kortix is the recommendation. 3,000+ apps in a click, plus MCP, OpenAPI, Postman, GraphQL and raw HTTP; connector credentials are brokered server-side and never enter the machine. One isolated sandbox per session. Session work reaches main through a change request. Merge is default-deny for agents. Run it on Kortix Cloud, in your VPC, or on your own on-prem network. Self-host is free (Read the docs). A team weighing the whole field first can read the open-source Copilot alternatives list and what Microsoft Copilot is, or the other lane on Copilot for Teams. For the longer written case, Read the guide.
Yes. Kortix reaches 3,000+ apps in a click, plus MCP, OpenAPI, Postman, GraphQL and raw HTTP, and connector credentials are brokered server-side and never enter the machine. Onyx indexes 40+ enterprise connectors, and Open WebUI feeds knowledge bases from sources including Google Drive and OneDrive.
Yes. Run Kortix on Kortix Cloud, in your VPC, or on your own on-prem network, and self-host is free. Onyx runs entirely in your cloud or on bare metal, and Open WebUI is built to run entirely offline.
The data stays where the team deploys the system. Kortix keeps company memory and connectors in a git repo you own, Onyx answers over your own index, and Open WebUI runs entirely offline. Each can run inside infrastructure you control.
No. The in-app assistance inside Word, Excel, PowerPoint, Outlook and Teams is Microsoft's own strength. An open-source system takes the other job: agent work across your tools, landed through a review.
Start with one job and grow from there.