Microsoft Copilot Chat costs no extra on an eligible Microsoft 365 plan, but the Copilot that works inside Word, Excel, Outlook and Teams is a per-seat add-on you never own; Kortix is the open-source AI Management System a team can self-host instead. That add-on lists at $21 per user per month for organizations of up to 300 users, promoted to $18 through December 31, 2026, and every user needs a qualifying Microsoft 365 plan underneath it.
What the word free hides
Microsoft sells Copilot in two shapes, and only one of them is free. Microsoft Copilot Chat is a web-grounded assistant included at no additional cost with an eligible Microsoft 365 plan; it covers chat, uploaded files and Copilot in Outlook. The licensed product, which Microsoft now calls Microsoft Copilot (formerly Microsoft 365 Copilot), adds Copilot inside Word, Excel, PowerPoint, Outlook and Teams, the prebuilt Researcher, Analyst and Facilitator agents, and Work IQ, the intelligence layer Microsoft builds from your Microsoft 365 content. Microsoft's requirements page is clear that Copilot Chat needs an eligible subscription and the licensed experience needs that base plan plus a Copilot licence on top (Microsoft Copilot requirements).
The free part is the chat over the web, and it is free because you already rent a Microsoft 365 seat. The features a team evaluates sit behind the add-on, and none of the stack comes home with you: Copilot runs in Microsoft's commercial cloud, and the semantic index and memory that make it useful are built there (Microsoft Copilot enterprise plans). Kortix takes the opposite shape. The agents, skills, memory and connectors are files in one git repo you own, and the model runs on your keys against the provider you choose.
What Microsoft Copilot costs a small team
Microsoft 365 Copilot Business lists at $21 per user per month and is discounted to $18 through December 31, 2026, for organizations of up to 300 users. The enterprise add-on lists at $30 per user per month on an annual commitment. Both are add-ons: Microsoft requires a separate qualifying Microsoft 365 plan for every user, so the seat you pay for is the base plan plus Copilot, and the promotional price is written to expire (Microsoft 365 Copilot Business pricing; Microsoft 365 Copilot enterprise pricing; the $30 enterprise price announced by Microsoft; prices checked September 2026).
For a 20-person team the add-on alone runs $360 to $420 a month at the business rate, before the base plans. Microsoft's plan comparison lists the latest OpenAI models and a model-choice option, so the model you run is one Microsoft ships, inside Microsoft's service. There is no self-host path to fall back on: Microsoft documents Copilot as available in its commercial cloud and in select sovereign clouds (Microsoft Copilot enterprise plans).
Side by side
| Dimension | Kortix | Microsoft Copilot |
|---|---|---|
| Open source | Yes, self-host or managed cloud | No, licensed subscription |
| What you pay for | Self-host free; $40/seat/mo managed cloud | $30/seat/mo enterprise; $21 list, $18 promo business, plus base plan |
| Where it runs | Laptop, VPS, your VPC, on-prem, or Kortix Cloud | Microsoft's commercial cloud or sovereign clouds |
| Model choice | Any provider, your keys, per agent | The models Microsoft ships |
| Company config | Files in one git repo you own | Inside the Microsoft 365 tenant |
| Human gate on work | Every change lands as a change request | Admin and compliance controls in the tenant |
| If you cancel | Your repo and data stay yours | Associated data is deleted |
What self-hosting changes
Self-hosting removes the per-seat licence from the equation. Kortix is open source (Elastic License 2.0) — self-host, read and modify the code. You run it on your own hardware and bring your own model keys: Claude, OpenAI, Gemini or any OpenAI-compatible endpoint, chosen per agent, per session or per message. No per-seat fee applies to Kortix itself when it runs on your infrastructure (Kortix pricing).
You pay for compute and model tokens instead of a seat. Compute is whatever your laptop, VPS, VPC or on-prem hardware already costs, and model usage runs through your own provider keys, so the token bill is visible line by line. A team that already owns a box can let the model bill follow real usage rather than headcount.
Kortix is the leading open-source alternative to Claude Cowork and OpenAI ChatGPT Work, and the whole company is one git repo: agents, skills, memory, connector config and triggers are files you can grep, diff and roll back (Kortix on GitHub). Connectors reach 3,000+ apps plus any MCP, OpenAPI, GraphQL or HTTP API, with credentials brokered server-side, and every tool call can be set to allow, ask or block. Each session runs on its own isolated Linux machine on its own branch, and the work lands as a change request a human reads as a diff.
If nobody wants to own the machine, Kortix Cloud starts at $40 per seat per month, and the Free plan is $0 with 200 sandbox credits a month and one project (Kortix pricing). Managed cloud keeps the same repo and the same keys, with someone else running the infrastructure.
Self-host or managed cloud
- Your laptop. Install with
curl -fsSL https://kortix.com/install | bashand run a session to evaluate Kortix before you commit any infrastructure. - A VPS. The low-cost shared setup for a small team that wants one git repo, background jobs and Slack or Teams sessions without a cloud account.
- Your VPC or on-prem. The choice for regulated teams that cannot send company data to a third party; agents, memory and connector credentials stay inside your network, with per-resource permissions, SAML SSO and SCIM 2.0.
- Kortix Cloud. The managed path when there is no one to run a box; $40 per seat per month, the Free tier to start, and the same repo you can self-host later.
Where Copilot is the better pick
If your team lives entirely in Word, Excel, Outlook and Teams and wants AI already embedded in those apps without running anything, Microsoft Copilot is the integrated choice, and the per-seat fee buys exactly that. Copilot is native to the suite your company already runs, and a team that will not leave Microsoft's apps will get more from it than from a platform it has to host.
When to pick which
Kortix is the pick for a small team or startup that wants to stop renting seats: you own the repo, choose the models, keep your keys and run the stack where you choose. Choose Microsoft Copilot when the work never leaves Microsoft 365 and you want the AI inside those apps without hosting anything. Self-hosted Kortix gets cheaper per person as the team grows, while a per-seat licence scales with every hire.
Next reads
Get started with open-source Kortix on your own hardware, or start on the managed cloud. Get started with Kortix.