Article

An opinionated guide to which AI to use to do stuff

Ethan Mollick (One Useful Thing) · oneusefulthing.org

A Wharton professor's regular guide: any free model for low-stakes questions, ChatGPT or Claude for real work, and where Google, Copilot and voice fit.

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It answers 11 questions

  1. ChatGPT, Claude, Gemini or Grok: which AI assistant should I use for work?
  2. I'm new to AI. Which assistant should I start with: ChatGPT, Claude, Gemini, Copilot, Meta AI or another?
  3. Is the free version of ChatGPT, Claude or Gemini enough, or should I pay?
  4. Should I use more than one AI assistant, and can I move what one knows about me to another?
  5. How do I choose between a fast model and a thinking model inside ChatGPT, Claude or Gemini?
  6. Which AI tool helps write and format documents?
  7. Is voice mode worth using, and which AI phone app is best for talking to?
  8. Is the AI already inside WhatsApp or Microsoft Office good enough, or do I need a separate app?
  9. How do I use Gemini well, on my phone and in Google apps?
  10. What are the best AI tools right now, and which ones are free?
  11. What is Microsoft Copilot, and is it worth using at work?

Read with it

  1. Anthropic's comparison of Claude Free, Pro and Max, including memory, voice mode and the number of projects each plan allows. claude.com Tool Plans & pricing | Claude Anthropic
  2. Google's comparison of the free Gemini app with AI Plus, Pro and Ultra, including which plans get the stronger models. gemini.google Tool Google AI Pro & Ultra: get access to Gemini 4 Argon & more Google
  3. OpenAI's own table of Free, Go, Plus and Pro: what each includes, from GPT-6 chats and memory to voice, projects and deep... chatgpt.com Tool ChatGPT Plans and Pricing OpenAI
  4. OpenAI's dated log of every change, including the India Go launch at Rs 399, the end of the free year and the new voices. help.openai.com Article ChatGPT release notes OpenAI Help Center
  5. The same page as shown in India, in rupees: free plan on a Flash-Lite model with Deep Research, Gemini Live and Gemini... gemini.google Tool Google AI plans (India) Google
  6. Usage data on ChatGPT, Gemini and Claude, including how many people use more than one and how fast Gemini and Claude grew in... a16z.com Article The Top 100 Gen AI Consumer Apps, 6th Edition Andreessen Horowitz
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