Microsoft Copilot vs ChatGPT · reviewed September 3, 2026
Copilot is the trick question of this list: it is not merely similar to GPT — it runs OpenAI’s GPT models, licensed through the Microsoft partnership. Under the hood the similarity is near-total; everything that differs is the wrapper. Microsoft’s wrapper happens to include a surprisingly generous free tier — no published cap on everyday text, Think Deeper and voice opened to free users, 15 image generations a day — and the one thing OpenAI cannot offer: Copilot inside Word, Excel, Outlook and Teams.
Independent guide by SimilarToGPT.com; not affiliated with Microsoft or OpenAI. Verify plans on the official sites — they change.
The real difference
Copilot’s Smart mode runs on GPT-5-class models, with GPT-5.5 Instant rolling out to Copilot Chat as of mid-2026. The catch: you mostly don’t choose. Microsoft routes your request to whatever it deems fit — the latest models “off-peak” on free, priority access on Pro — where ChatGPT lets you see and often pick the model tier you’re getting. Same engine, less say over which gear it’s in.
ChatGPT Free gives unlimited text but caps the extras. Copilot Free publishes no message cap either and threw open features Microsoft once paywalled: Think Deeper (its reasoning mode) and voice went free back in 2025, and free users get 15 image-generation boosts a day. For a no-account-upgrade user who wants reasoning, voice and images occasionally, Copilot’s free bundle is quietly one of the best in this guide.
The real pitch is not the chat window, it is Copilot drafting inside Word, building formulas in Excel, triaging Outlook and recapping Teams meetings. That requires the paid Microsoft 365 side — consumer bundles from $1.99 to $19.99/month, Copilot Pro at $20, business seats at $18–$25.20 per user — and it is the one capability no amount of ChatGPT subscription buys. If your day is lived in Office files, this comparison is not really about chatbots.
Side by side
Checked September 3, 2026 against the sources at the bottom of this page. Prices in USD; limits move often.
| Microsoft Copilot | ChatGPT | |
|---|---|---|
| Maker | Microsoft (models licensed from OpenAI) | OpenAI |
| Models | GPT-5-class Smart mode; GPT-5.5 Instant rolling into Copilot Chat; routed by Microsoft, limited user choice | GPT-5.6 family (Sol, Sol Pro, Luna, Terra), routed by plan |
| Free tier | No published text cap; latest models “off-peak”; Think Deeper and voice free; 15 image boosts/day | Unlimited everyday text since Aug 2026; reasoning modes, images, voice and file uploads (3/day) capped |
| Paid plans | Copilot Pro $20/mo (100 image boosts/day, priority model access, Researcher agent); Microsoft 365 bundles $1.99–$19.99/mo; business $18–$25.20/user/mo | Go $8 (select countries), Plus $20, Pro $100 (5×) / $200 (20×) |
| Office integration | Native in Word, Excel, PowerPoint, Outlook, Teams (on qualifying plans) | None — connectors and file uploads instead |
| Custom bots | No Custom-GPT-style store | Custom GPTs + store |
| Where it runs | Windows (built in), Edge, Microsoft 365 apps, copilot.microsoft.com, mobile | chatgpt.com, desktop and mobile apps |
| Published limits | Few — capacity managed by routing and peak-time priority | Caps published per plan and feature |
Switching
Practically everything, because it is the same model family: your prompting habits produce familiar answers, often near-identical ones. There is no export ritual worth doing — sign in with a Microsoft account and go. If you are on Windows it is already on your taskbar, which is precisely Microsoft’s plan.
The power-user layer. No Custom GPT store, no Sora, projects and memory are shallower, and OpenAI’s newest features reach ChatGPT first — Copilot inherits them later, sometimes never. You also trade published limits for routing opacity: ChatGPT tells you what Plus buys; Copilot says “priority access” and leaves peak-time behaviour to be discovered.
Run your five most-used ChatGPT prompts through Copilot Free side by side — for many people the answers are close enough that the $20 question becomes purely ecosystem. Then the real test: open a document you actually owe someone in Word and try Copilot on it (a Microsoft 365 trial covers this). If the Office half earns its keep, Copilot wins on integration; if not, ChatGPT’s app is the deeper chatbot.
The honest part
“No published cap” cuts both ways: at peak times free users are quietly moved to lesser models, and there is no meter telling you it happened. ChatGPT’s explicit caps are less romantic but easier to plan work around. If you need a specific model at a specific moment, Copilot is the wrong place to need it.
Copilot inherits OpenAI’s models but not OpenAI’s roadmap. New capabilities debut in ChatGPT, arrive in Copilot on Microsoft’s schedule, and some (Custom GPTs, Sora) never cross at all. Buying Copilot Pro to get “ChatGPT Plus from Microsoft” buys yesterday’s ChatGPT with better Office manners.
Copilot, Copilot Pro, Copilot Chat, Microsoft 365 Copilot, plus consumer bundles from $1.99 Basic to $19.99 Premium and business seats at $18 or $25.20 depending on billing — buying the wrong Copilot is a genuine risk. Decide first whether you want the chatbot (Pro, $20) or Copilot-in-Office (a 365 plan), because they are different purchases.
Sources
Checked September 3, 2026.
FAQ
Under the hood, nearly: Copilot runs OpenAI's GPT models (GPT-5-class Smart mode, with GPT-5.5 Instant rolling into Copilot Chat) via the Microsoft partnership. What differs is the wrapper — Microsoft routes model choice for you, integrates with Office, and lacks ChatGPT's Custom GPTs, Sora and newest features, which debut on ChatGPT first.
Yes, and generously: copilot.microsoft.com publishes no message cap for everyday text, Think Deeper (reasoning) and voice are free, and free users get 15 image-generation boosts a day. The trade is opacity — at peak times free traffic can be routed to lesser models without notice.
Same price, different bets. Copilot Pro buys priority model access, 100 image boosts a day, the Researcher agent and Copilot inside Office apps on qualifying plans. ChatGPT Plus buys published limits, model choice, Custom GPTs, Sora and first access to OpenAI's newest features. Office-centric work favours Copilot Pro; everything else favours Plus.
No — the chatbot at copilot.microsoft.com and the Windows app work free without a subscription. You need a Microsoft 365 plan (consumer $1.99–$19.99/month, or business seats $18–$25.20/user/month) only for Copilot inside Word, Excel, Outlook, PowerPoint and Teams.
Microsoft states GPT-5-class models power Smart mode, with GPT-5.5 Instant rolling out to Copilot Chat as of mid-2026, and routes requests among models based on load and plan. Unlike ChatGPT, you generally cannot pin a specific model version — that is the main practical difference for demanding users.
Few published ones. Text chat has no stated cap; images are metered (15 boosts/day free, 100 on Pro); model access is 'latest off-peak' on free and 'priority' on Pro. In practice capacity is managed by invisible routing rather than visible counters — fine for casual use, frustrating if you need guarantees.
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