Quick Answer
Copilot's strength is that it works inside your Microsoft apps and already knows your emails, files and meetings. ChatGPT's strength is everything outside them: images, agent mode, scheduled tasks and a large plugin directory. A Microsoft 365 team gets the most from Copilot for in-app work and ChatGPT for the rest, as long as both follow the same company instructions.
First, Which Copilot?
"Copilot" means different things depending on your licence:
- Copilot Chat comes free with eligible Microsoft 365 business plans. It's a secure AI chat, but it doesn't read your mailbox or files on its own.
- Microsoft 365 Copilot is the paid add-on. It works inside Word, Excel, PowerPoint, Outlook and Teams, and draws on your organisation's emails, files and meetings through Microsoft Graph. The Business version lists at about USD 21 per user per month, on top of your Microsoft 365 plan (Microsoft 365 Copilot Business).
- Copilot Studio is where you build your own agents. Most small teams don't need it to start.
When people compare ChatGPT with Copilot, they usually mean the paid Microsoft 365 Copilot.
Where Copilot Is Stronger
It's already where the work is. Copilot drafts in Word, summarises email threads in Outlook, builds slides in PowerPoint and recaps Teams meetings, without copying anything into another window.
It knows your organisation. Because it reads through Microsoft Graph, Copilot can answer "what did we agree with this client last month?" from your own email and files, within each person's existing permissions.
It fits your IT setup. Licences, data protection and admin controls sit in the Microsoft 365 admin centre you already use.
It now uses more than one AI model. Microsoft added Anthropic's Claude models to Copilot's Researcher agent and Copilot Studio, alongside OpenAI's (TechRepublic). Even Microsoft doesn't rely on a single AI.
Where ChatGPT Is Stronger
Work outside Office. ChatGPT creates images, runs agent mode across websites and multi-step jobs, and sends scheduled briefings (eWeek on ChatGPT features).
A bigger toolbox. The Plugin Directory brings skills, apps and templates into one place, and connectors reach SharePoint, Google Drive, Slack and GitHub.
One price, no add-on. ChatGPT Business is USD 20 per user per month billed annually, or USD 25 monthly, from 2 users (ChatGPT pricing). It doesn't depend on which Microsoft plan you have.
People already know it. Many staff use ChatGPT at home, so adoption is often quicker.
What a 10-Person Team Pays
At list prices, before any promotions:
| Setup | Per person a month | 10 people a month |
|---|---|---|
| Copilot Chat only (included with Microsoft 365) | USD 0 extra | USD 0 extra |
| Microsoft 365 Copilot Business | about USD 21, on top of Microsoft 365 | about USD 210 |
| ChatGPT Business, billed annually | USD 20 | USD 200 |
| Both | about USD 41 | about USD 410 |
Microsoft and OpenAI both change prices and run promotions, so check the current figures before you decide.
Using Both Without Doubling the Work
The common setup is Copilot for work inside Microsoft apps and ChatGPT for everything else. The risk is that each one learns your business separately:
- Copilot reads what's in your Microsoft 365, but not the rules and templates you've set up in ChatGPT.
- ChatGPT's projects and plugins don't carry into Copilot.
- When a price list or proposal template changes, someone has to update both.
Try It: Decide by Task, Not by Tool
- Write down where your team spends most of its time: Outlook and Word, or browsers and other apps.
- Mark which tasks need your organisation's own emails and files. Those suit Copilot.
- Mark which need images, research across the web or tasks that run on their own. Those suit ChatGPT.
- If you end up with both lists, plan for both, and decide where your shared instructions will live.
Where Contexta Fits
Contexta keeps one set of company context, knowledge and skills for every AI your team uses. A skill tells your AI what to do. Your knowledge base shows it how, in detail. Your company context tells it who it's for. The Contexta harness brings them together, in every AI.
ChatGPT is a tested Contexta setup. Copilot isn't tested yet, so check Integrations before you plan around it. Your knowledge base stays in your own SharePoint or Google Drive either way, and Contexta doesn't store or index your documents.