Which AI Should You Use in February 2026?
Source: A Guide to Which AI to Use in the Agentic Era by Ethan Mollick (Feb 18, 2026)
Practical Guide: Which AI Should You Use in February 2026?
The original article by Prof. Ethan Mollick goes much deeper into each of these topics with examples and comparisons β it's well worth reading in full β but here's a practical summary of the key takeaways.
The Big Picture
AI is no longer just chatbots. You used to type a question and get an answer. Now AI can actually do tasks for you β research, create spreadsheets, build presentations, organize files. To pick the right tool, you need to understand three simple concepts:
3 Things That Matter
| Concept | What It Means | Analogy |
|---|---|---|
| Model | The AI "brain" β how smart it is | The engine in a car |
| App | The website or program you use to talk to the AI | The car itself |
| Harness | The tools the AI can use to get work done | What's attached to the car (trailer, plow, etc.) |
The Big Three AI Systems
All three are good. Pick one and start there:
- ChatGPT (by OpenAI) β chatgpt.com β $20/month
- Claude (by Anthropic) β claude.ai β $20/month
- Gemini (by Google) β gemini.google.com β $20/month
Rule #1: Always Select the Smart Model
This is the single most important tip. The default/free models are significantly worse. After paying, you still need to manually pick the powerful version:
| System | Select This | Avoid This |
|---|---|---|
| ChatGPT | GPT-5.2 Thinking Extended | "GPT-5.2" (auto mode picks weak models) |
| Claude | Opus 4.6 (with extended thinking on) | The default model |
| Gemini | Gemini 3 Pro or Thinking | Gemini 3 Flash |
What Each System Does Best
ChatGPT β The most features in one place. Good at math, analysis, image creation. Can make spreadsheets and presentations directly. Best for: all-rounders who want one tool that does a bit of everything.
Claude β Best writing quality and best "agent" tools. Claude Cowork can work on your desktop files autonomously. Claude for Excel is a game-changer for spreadsheet work. Best for: writing-heavy work, document processing, people who want AI to do tasks independently.
Gemini β Best image generation (nano banana), best video creation (Veo 3.1), and NotebookLM for research. The chatbot harness lags behind the other two though. Best for: creative/visual work, students, researchers who need to digest many documents.
Beyond Chatbots: Tools Worth Knowing
| Tool | What It Does | Who It's For |
|---|---|---|
| NotebookLM (Google, free) | Upload documents, papers, videos. Ask questions, make slides, generate podcast discussions from your material. | Students, researchers, anyone drowning in documents |
| Claude Cowork (Anthropic) | Works on your desktop like a virtual assistant β organizes files, pulls data from PDFs, drafts summaries. | Office workers, anyone with repetitive computer tasks |
| Deep Research (all three have it) | AI spends minutes doing thorough internet research and writes a report with sources. | Anyone who needs to research a topic properly |
Getting Started: 3 Steps
- Pick one (ChatGPT, Claude, or Gemini), pay $20/month, and select the advanced model.
- Use it for real work β not toy questions. Upload an actual document. Give it an actual task. Have a back-and-forth conversation.
- When comfortable, try NotebookLM (free) or Claude Cowork to see AI that goes beyond chat.
The Key Takeaway
AI that does things is fundamentally more useful than AI that says things. The shift from "chatbot you talk to" to "agent that works for you" is the biggest change since ChatGPT launched. Start learning to use it that way now.