
Why Does AI Hallucinate? Causes and How to Spot It
AI chatbots can state wrong facts with total confidence. Here is why that happens and how to catch it.

ChatGPT vs Copilot โ which AI assistant should you use? Both can write, answer questions, summarize documents, and help with code. But they are built for different people. ChatGPT is a general-purpose chatbot with a huge set of tools and a big user base. Copilot is Microsoft’s AI assistant, built to work inside Windows, Edge, and Microsoft 365 apps like Word, Excel, and Outlook. This comparison covers price, models, features, and daily use, so you can pick the one that fits your work.

If you are comparing AI chatbots in general, our main guide on ChatGPT vs Claude covers another popular matchup. And for a second comparison in this series, see Claude vs Gemini โ together, the three guides give you a full picture of the main chatbot options.
Both tools have a free version, and both are useful without paying.
ChatGPT’s free plan gives you access to the standard model with daily limits on messages, image generation, and file uploads. It is a real daily tool for simple tasks, and it is enough for many casual users.
Copilot’s free version is built into Windows and Edge, and you can also use it on the web and in a mobile app. It gives you chat, image generation, and web-grounded answers at no cost, with its own usage limits. Because it is built into Windows, many people already have it without installing anything.
For free use, the difference is small. ChatGPT’s free plan feels a bit more generous for long chats and creative work, while Copilot’s free version is more convenient if you live in Windows and Edge. Neither free plan is a full replacement for the paid versions if you use AI all day.
ChatGPT’s paid plans are simple: Plus at $20 a month for individuals, Pro at $200 a month for heavy users, and Team and Business plans for groups. Plus is the plan most paying users pick, and it removes the free plan’s limits while adding newer models and features.
Copilot’s paid side is more spread out. Copilot Pro is a monthly subscription for individuals that adds priority access, faster replies, and Copilot inside Microsoft 365 apps like Word and Excel. Microsoft 365 Copilot is a separate business add-on for companies already paying for Microsoft 365, priced per user per month. The exact price depends on your Microsoft 365 plan and region, so check Microsoft’s pricing page for the current number.
The key difference: ChatGPT’s paid plans are one simple ladder. Copilot’s paid plans depend on what Microsoft products you already pay for. If you already use Microsoft 365 for work, adding Copilot can feel natural. If you do not, ChatGPT Plus is the simpler purchase.
ChatGPT runs on OpenAI’s models, which are known for strong general writing, reasoning, and coding. Newer models handle long documents, complex questions, and multi-step tasks well. OpenAI updates its models often, and Plus and Pro users get access to the newest ones first.
Copilot runs on Microsoft’s setup, which is built on OpenAI’s models as well, tuned for Microsoft’s products and for web-grounded answers. In practice, Copilot is strong at answering questions with fresh web information and at working with your files in OneDrive and Microsoft 365. For pure chat quality โ long writing, creative work, and tricky reasoning โ ChatGPT usually has a small edge.
For most everyday questions, both are good enough. The difference shows up on hard tasks: long analysis, complex code, and creative writing, where ChatGPT’s models tend to do a little better.
This is the biggest difference between the two, and it is the one that should decide your pick.
Copilot is built into Microsoft 365. Inside Word, it can draft and rewrite text. Inside Excel, it can explain formulas and build charts from your data. Inside Outlook, it can summarize long email threads and draft replies. Inside Teams, it can summarize meetings. If your workday runs on Microsoft 365, Copilot meets you where you already work โ no copying and pasting between apps.
ChatGPT has a different kind of reach. It has a large set of built-in tools โ image generation, code running, file analysis, web browsing, and voice โ plus a wide range of third-party integrations and apps. You can connect it to your calendar, your notes, your code editor, and many other tools. Its ecosystem is broader, but it is not built into Word or Excel the way Copilot is.
So the question is simple: do you work inside Microsoft 365 all day, or do you work across many different apps? If the answer is Microsoft 365, Copilot has the home advantage. If you work across many tools, ChatGPT’s wider ecosystem fits better.
Both tools can write and explain code, but they serve different coding habits.
ChatGPT is a strong coding helper for general work: writing functions, debugging errors, explaining code, and building small scripts. Its code tools and file analysis make it easy to paste in a file and ask for changes. Many developers use ChatGPT as a second pair of eyes on their code.
Copilot has a special advantage for developers who use GitHub, because GitHub Copilot is a separate Microsoft product built for code completion inside editors like VS Code. The chat Copilot in Windows and Edge is not the same as GitHub Copilot, but the two share the same idea: AI that helps you write code where you already write it. If you code in VS Code all day, GitHub Copilot is worth a look on its own. For general coding questions in a chat window, ChatGPT is the more flexible tool.
Both tools can generate images from a text prompt. ChatGPT’s image generation is built into the chat โ you describe the image, it creates it, and you can ask for changes in plain language. It is strong at following detailed prompts and at editing an image you upload.
Copilot also generates images, powered by Microsoft’s image tools, and it works well for quick, simple images. In practice, ChatGPT’s image tools feel more flexible for detailed or creative work, while Copilot’s are fine for fast, simple images. For most users, either one covers basic image needs.
Both tools can search the web for current information, but Copilot leans on it more. Copilot is built to give web-grounded answers with links to sources, which makes it a good fit for questions about current events, prices, and news. It often shows its sources clearly, so you can check them.
ChatGPT also browses the web and can cite sources, but its strength is in reasoning over what it finds, not just fetching it. If you want a quick, sourced answer to “what happened today,” Copilot is often faster. If you want a deep answer that pulls together several sources, ChatGPT is often stronger.
Either way, check the sources on anything that matters. Both tools can still get facts wrong, even when they browse the web.
Privacy matters when you paste work documents or personal information into a chatbot. Both companies say they protect user data, but the details differ by plan.
ChatGPT’s free and Plus plans may use your chats to improve the model unless you change the setting. You can turn off training on your data in the settings, and Business and Enterprise plans have stronger data controls. Always check the current policy before pasting sensitive work.
Copilot’s business plans come with Microsoft’s enterprise data protections, which many companies trust for work documents. The free consumer version has fewer guarantees. If you work for a company with strict data rules, ask your IT team which tool is approved โ many companies have already chosen one, and that choice matters more than any feature list.
As a rule, do not paste passwords, private customer data, or confidential business information into any consumer chatbot plan.
One risk is specific to Copilot. Because Copilot reads your files through Microsoft Graph, it can surface a document that was shared too widely inside your company โ for example, a salary sheet or a client contract that someone shared with “everyone” by mistake. Copilot does not break permissions, but it can quote files that people did not know were visible to others. Before a company rolls out Copilot, IT should check sharing settings and clean up over-shared files. ChatGPT has a different risk: on Free and Plus plans, your chats may be used to train models unless you turn that setting off.
Many people do. Use Copilot inside Word and Outlook for work documents, and ChatGPT for writing, coding, and creative work. There is no rule that says you must pick one. The free versions of both cost nothing, so try each for a week and keep the one โ or the pair โ that fits your day.
For companies on Microsoft 365, Copilot’s business plans offer stronger enterprise data protections. For personal use, neither is clearly safer โ both can get facts wrong, and you should not paste sensitive information into either consumer plan.
ChatGPT has a wider set of built-in tools and integrations outside Microsoft apps โ code running, file analysis, and many third-party connections. It is also usually a little stronger at long creative writing and complex reasoning.
Yes, Copilot has a free version built into Windows, Edge, and the web. Paid upgrades like Copilot Pro add more features and Copilot inside Microsoft 365 apps.
For general chat, writing, and coding, ChatGPT usually has a small edge. For work inside Microsoft 365 apps, Copilot is better because it is built in. The right pick depends on how you work.
For Microsoft 365 users, Copilot can cover many daily tasks. But ChatGPT’s wider tools and stronger general chat mean many people keep both, using each where it is strongest.
ChatGPT is more flexible for general coding questions in a chat window. Developers who code in VS Code should also look at GitHub Copilot, which is built for code completion inside the editor.
They are related but not the same. Copilot is built on OpenAI’s models, tuned for Microsoft’s products and web-grounded answers. ChatGPT runs OpenAI’s models directly, with its own tools and tuning.

AI chatbots can state wrong facts with total confidence. Here is why that happens and how to catch it.

Claude and Gemini both cost about $20 a month โ but they are built for different work. Here is how they compare on writing, coding, research, limits and privacy.

ChatGPT and Claude both cost $20 a month โ but they are not the same tool. Here is how they compare on writing, coding, price and privacy.