ChatGPT vs Claude vs Microsoft Copilot: The Q4 2026 Answer
All three now live inside Word and Excel, and all three have agents. Here is what actually separates them, what each one costs, and which to buy first.
By John Martines · September 29, 2026 · 9 min read
In February this was a chatbot comparison. Now all three live inside Word and Excel, all three have agents, and the real differences are where your work already lives, how each one bills you, and what you let it touch.
In February this was a chatbot comparison. Which one writes better, which one codes better, which one makes things up less. I gave them stars.
That article is retired, because the question changed. All three now live inside Word and Excel. All three have agents that do work while you're somewhere else. Microsoft cut its price, and OpenAI launched a new kind of agent this morning. The real differences now are where your work already lives, how each one bills you once it starts doing things on its own, and what you're willing to let it touch.
Here's the Q4 2026 answer, with the dates and prices on everything so you can check me.
- Microsoft cut the price and moved the goalposts. Copilot Chat is included in every Microsoft 365 business plan. The full Copilot for small companies, now called Copilot Business, is $21 a user on an annual plan, with an $18 promo through December 31, 2026. That's well under the $30 most people still quote. On September 25 Microsoft rebuilt the whole thing around Home, Code and Autopilot.
- OpenAI shipped new models, new agents and a new rule. GPT-6 Sol and Luna arrived September 22. The ChatGPT add-in reached Word on September 17 on every plan, Free included, and it turns on by default October 1. Today, at DevDay, OpenAI launched "dots," always-on agents with their own computer and browser. And custom GPTs are being retired in favor of plugins.
- Anthropic went after small business directly. Claude has worked inside Excel, Word and PowerPoint on every paid plan since May. On September 15, Claude for Small Business grew to 43 ready-made workflows and 27 new connections, including Shopify, Xero, Gusto, Square and Stripe. On September 22, Opus 5.5 replaced Opus 5 on every paid plan.
None of that is hype. It's just a lot of change for seven months, and most of it landed in the last three weeks.
What it is now. Copilot is AI inside the Microsoft 365 you're already paying for. Copilot Chat comes free with Business Basic, Standard and Premium. It's a secure work chat, and in Outlook it can answer questions about your own email and calendar. Copilot Business adds the part people mean when they say "Copilot": it works across your email, meetings, chats and SharePoint files inside Word, Excel, PowerPoint, Outlook and Teams.
The September 25 rebuild puts Word, Excel and PowerPoint inside Copilot's new Home screen, adds Code (describe a tracker or a small app and it builds it inside your tenant), and adds Autopilot, an agent that follows up on threads and runs recurring work. Home and Code roll out through Microsoft's early-access Frontier program in the coming weeks. Autopilot is in private preview.
What it costs. Copilot Business is $21 per user per month on an annual plan, $18 on the promo through December 31, 2026. The bundles are simpler: Business Standard with Copilot is $23.50, Business Premium with Copilot is $32. Then there's the meter. Agents that work on their own, like Copilot Cowork, bill in Copilot Credits at a penny each, and the number of credits per task varies with the work. The good news: metered agents stay off until an admin turns on pay-as-you-go billing.
Pick it if your business already runs on Outlook, Teams and SharePoint, and the knowledge you need lives there. Nobody else reads your company's email and files from the inside the way Copilot does.
The honest case against. Copilot is only as good as your SharePoint permissions. If "everyone can see everything" is how your file shares grew up, Copilot will find that out before you do. And the meter means your bill is now a seat plus a phone bill. Set the cap before the first agent runs.
What it is now. ChatGPT is still the one most people have on their phone, and that matters more than any benchmark. GPT-6 Sol handles everyday work, and OpenAI says it makes about half as many mistakes as the model before it. ChatGPT Work is its agent for longer jobs. It researches, works across connected apps, and hands back finished documents, spreadsheets and decks while you watch and approve. Voice now works in Work too, so you can talk a document into existence on the drive between jobs.
As of this morning there are also dots. A dot is an always-on agent that runs on OpenAI's top model, with its own cloud computer and browser, and works toward the goals you give it around the clock. That's real, and it's worth watching. But today it comes only with the Pro plan and the $100 Business Premium seat, one dot each (Enterprise admins can approve a trial), and not in the EU or UK. Most small businesses on the standard seat won't have one yet.
What it costs. ChatGPT Business is $20 per user per month billed annually, or $25 monthly, with a two-seat minimum. A Premium seat is $100 a month on an annual plan ($125 monthly) for five times the usage.
Pick it if your team already reaches for it, you want the widest set of connected apps, or voice and images matter to how you work.
The honest case against. It changes fast, and some of that change is homework. If you built custom GPTs, OpenAI is retiring them and moving you to plugins. Enterprise workspaces have a December 11, 2026 date, and your instructions and knowledge files carry over but custom actions don't. And the Word add-in turning on by default October 1 means your staff may have AI in their documents on Thursday whether you decided anything or not.
What it is now. Claude is built for long documents, careful writing and work you'd want a steady person to do. Opus 5.5, its top model since September 22, is built with a one-million-token context window, which is room for a stack of long contracts at once. It works inside Excel, Word and PowerPoint on every paid plan, and it can edit a contract with tracked changes, update a model without breaking your formulas, or rebuild a deck on your slide master.
The newest piece is Claude for Small Business: 43 ready-made workflows for things like a weekly financial brief, lead follow-up, proposals and bookkeeping reconciliation, working with QuickBooks and, since September 15, Shopify, Xero, Gusto, Square, Stripe and Zapier. Every workflow starts in approval mode. Some stop short on purpose. It stages payroll in Gusto and leaves the submit button to you. And an employee who can't see something in QuickBooks can't see it through Claude either.
What it costs. Claude Team is $20 per seat per month billed annually, or $25 monthly, for teams of 2 to 150. It includes Claude Cowork, Claude Code, and the Office add-ins. A Premium seat is $100 a month annually ($125 monthly), and you can mix seat types.
Pick it if your work is words and documents: contracts, proposals, policies, reports, customer letters. Or if you want the workflows with the approval step built in.
The honest case against. It isn't already on your staff's phones, and it isn't already in your Microsoft bill. That means one more subscription and one more thing to teach. If nobody on your team writes much, you may not feel the difference.
| | Microsoft Copilot | ChatGPT | Claude | |---|---|---|---| | Starting price for a team | Copilot Chat included in M365 business plans; Copilot Business $21/user (annual), $18 promo to Dec 31 | $20/user annual, $25 monthly, 2-seat minimum | $20/seat annual, $25 monthly, 2 to 150 seats | | Lives inside | Word, Excel, PowerPoint, Outlook, Teams, and now its own Home | Its own app, plus add-ins for Word and Excel | Its own app, plus Excel, Word and PowerPoint add-ins (Outlook in beta) | | Reads your company files | Natively, across SharePoint, email and Teams | Through connected apps you approve | Through connectors you approve, including Microsoft 365 | | Agents | Cowork (metered), Autopilot in preview | ChatGPT Work; dots on Pro and Business Premium | Cowork, plus 43 small-business workflows | | What can surprise your bill | Copilot Credits at $0.01 each for agent work | Premium seats and extra workspace credits | Premium seats | | Trains on your business data? | Not by default on business plans | Not by default on business plans | Not by default on business plans |
That last row is the same across all three on purpose. Every business plan here says it doesn't train on your company's data by default. Check the admin setting anyway, and be wary of anyone who tells you only their favorite is safe.
Then you may not need any of these three first. Google Workspace Business Standard includes Gemini in Gmail, Docs and Meet, plus the Gemini app and Gemini Notebook for asking questions of your own documents. Try what you already pay for before you buy a fourth thing.
In February I wrote that you don't have to choose one. That's still true, but it's no longer the whole answer. Here's the order I'd do it in now.
- Use what you already pay for. If you're on Microsoft 365, turn on Copilot Chat for everyone. If you're on Google Workspace, use Gemini. That's free AI your staff can use today, inside tools your IT person already secures.
- Buy one paid assistant for the two or three people who write the most. ChatGPT if they already use it, Claude if the work is long documents or you want the approval-first workflows. Two seats, one month, then look at what they actually did with it.
- Add Copilot Business when the work is inside your Microsoft files. When people keep asking "what did we decide in that thread?" or "where's the latest version?", that's Copilot's job. Clean up your SharePoint permissions first.
- Put one set of rules over all of it. Which tools are approved, what never goes in, who approves an agent before it sends or pays anything. The tool matters less than the rules.
> Start with what's already in the building. Buy the second thing only when you can name the job it's for.
- Decide about the ChatGPT Word add-in before Thursday. It turns on by default October 1. Your admin can leave it on, turn it off, or limit it. Deciding is the point, and the [Staff AI Rules Kit](/tools/staff-rules) will write the rule for you.
- Set a spending cap before any agent runs. Copilot's metered agents stay off until an admin turns them on. Put the cap and the alerts in place first. The [Metered Bill Estimator](/tools/bill-estimator) suggests the number.
- Check what you're already paying for. Most small businesses own more AI than they use. Ten minutes with the [Already-Paid-For Finder](/tools/ai-finder) finds it.
The tools will change again by spring. They always do. What won't change is the order: know what you own, pick the job, write the rules, then let the software earn its seat.
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Sources and dates. Microsoft: "Introducing the new Copilot with Home, Code and Autopilot" (Microsoft blog, Sept 25, 2026); Microsoft 365 Copilot Business pricing (Microsoft Licensing and Partner Center, checked Sept 27, 2026); Copilot Credit rates (Microsoft Learn, Copilot Studio billing). OpenAI: "Introducing GPT-6 Sol and Luna" (Sept 22, 2026); ChatGPT for Word (OpenAI, Sept 17, 2026, on by default Oct 1); ChatGPT Work help article; Custom GPT retirement and migration FAQ (OpenAI Help Center, announced Sept 11, 2026); dots availability (9to5Google and OpenAI's DevDay recap, Sept 29, 2026); ChatGPT Business pricing (OpenAI Help Center, checked Sept 27, 2026). Anthropic: Claude Opus 5.5 (Anthropic and TechCrunch, Sept 22, 2026); Claude for Small Business update (Anthropic, Sept 15, 2026); Claude for Microsoft 365 (Anthropic support, general availability May 7, 2026); Claude Team pricing (Claude pricing page, checked Sept 27, 2026). Google: Google Workspace plan pages (checked Sept 27, 2026). Prices change often. Check the vendor's page before you buy.
*This replaces our February 2026 comparison.*