Comparison
Copilot or ChatGPT? The difference isn't in who writes better.
On text quality there's barely anything in it in 2026. Where they do diverge is context, governance and where your data ends up, and those are exactly the three things that decide it for an organisation.
The question behind the question
01 · The real difference
People asking this usually want to know which is smarter. That's the least useful criterion: on the tasks that make up office work, both do fine.
The distinction that matters is context. Copilot can reach your documents, mail, calendar and Teams conversations, through the permissions you already have. Ask for a summary of the project meeting and nothing has to be pasted. ChatGPT only knows what you give it. That makes it less handy for work inside your own files, and more nimble for work that stands apart from them.
The second distinction is administration. Copilot sits inside your existing tenant: the same login, the same permissions, the same agreements you already had with Microsoft. For an IT department that saves an entire project. ChatGPT for business has its own admin layer and its own contract, and that's work, manageable, but separate work someone has to do.
The third is what happens without a choice. In nearly every organisation we measure, some people already use something with a personal account. That isn't malice but convenience, and it's the one scenario where the answer is genuinely wrong: company data in a free consumer account. So choosing between two tools is less urgent than choosing to designate one at all.
Where we stand
We train on both and resell neither licence. That doesn't make us neutral, most of our clients are in Microsoft 365 and our examples come from there, but we have no stake in which way you go.
Side by side
02 · The facts
On the points that concern an organisation. Text quality deliberately isn't listed: the difference there is too small to base a choice on.
| On what | Microsoft 365 Copilot | ChatGPT |
|---|---|---|
| Sees your own documents and mail | Yes, via Microsoft Graph | Only what you paste in |
| Lives in Word, Excel, Outlook, Teams | Yes | No |
| Administered from your existing tenant | Yes | Separate, its own admin layer |
| Strong at standalone reasoning tasks | Reasonable | Yes, that's the strength |
| Works without Microsoft 365 | No | Yes |
| Free tier usable at work | Limited | Not advised |
| Cost per user per month | ± €28–30 | €0 to ± €23 |
Licence prices as of August 2026, excluding VAT. Both vendors change these regularly.
Which one when
03 · The trade-off
Copilot
When your work lives in your own files
You're already in Microsoft 365, the work revolves around documents, mail and meetings, and IT doesn't want a second admin layer. Then Copilot is the path of least resistance, and usually the fastest first payoff too.
ChatGPT
When your work stands apart from your files
Thinking work, analysis, code, working out scenarios, text that doesn't have to come from anywhere. Also if you're not in Microsoft 365, or when one team needs something the rest doesn't.
Both
When practice has already decided
More often than organisations think. Then the question isn't which you pick but which you designate for what, and what may go into neither. That's an agreement on one sheet of paper, not a procurement process.
What the choice doesn't solve
04 · The sober part
Both tools write convincingly, including when they're wrong. Both adopt your assumption rather than challenging it. And with both, the user decides whether the result is usable.
In every baseline we run, 'review' is the lowest column. Not because people are careless, but because nobody taught them what to look for in an answer that looks right. That score doesn't shift by buying a different licence. It shifts by having people practise on output with a demonstrable error in it.
That's also why we don't write this comparison as a sales page. Which tool you choose is largely irrelevant to our work: the modules are about the skill, not the buttons. Where it does matter (Excel analysis, building agents) sits in separate modules, so you don't pay for it if you're not going that way.
Questions when choosing
05 · Short answer
Can we use both?
Yes, and many organisations already do without realising it. The question isn't whether it's allowed but whether it's arranged: if half your people work with a personal ChatGPT account, you haven't made a choice, you have a blind spot. Make it explicit, agree what may go where, and record it.
Is ChatGPT unsafe for company data?
Not necessarily, it depends on the plan. In the business tiers your input isn't used to train models, just as with Copilot. The difference is where the data sits, who administers it, and how it relates to your existing agreements with Microsoft. With a free personal account the answer is simply: don't do that with company data.
Which is better in Dutch?
In 2026 there's barely anything in it; both write good Dutch. What does differ is the tone of the output: both lean formal and long-winded, and you don't fix that by switching tools but with a style guide and context. That's a skills question, not a product choice.
What does it cost per user?
Microsoft 365 Copilot runs around €28 to €30 per user per month on top of your existing licence. ChatGPT has a free tier, a cheap entry plan and Plus at around €23 per month, with separate business rates. With either, don't treat the licence as the whole cost: if nobody uses it, every euro of it is wasted.
Does the choice change the training?
The examples change, the skills don't. Framing a task, judging output and knowing what not to enter work identically in both. That's why the core sits in vendor-neutral modules, with product-specific subjects (Excel analysis, agents) kept separate.
Read on
- How does Copilot work?
A jargon-free explanation of what happens under the bonnet, with the limits included.
- AI training for employees
The skill that's identical in both tools, and why it weighs more than the choice.
- Prompts that actually work
Five patterns that work in both tools, and what goes wrong when you drop one.
The choice matters less than the level
Want to know where your people stand today, whichever tool they use? That's one five-minute measurement per person, and it also answers which product fits your work.