If you’ve used ChatGPT, you know how helpful it can be. But in 2025, it’s no longer the only AI assistant worth your time. Tech giants like Google and Microsoft are in the game, and a newer platform called Perplexity AI is making waves for its research capabilities.

So which AI tool is best for you? I tested all four—ChatGPT, Gemini, Copilot, and Perplexity—using the same prompts to see how they compare. Here’s what I found.

Perplexity AI: Best for Research with Sources

If you need real-time answers with trusted citations, Perplexity is the clear winner. When I asked, “What are the latest statistics on electric vehicle sales in the U.S.?”, it provided a clean, well-sourced answer with links to articles, government reports, and live data.

Perplexity is ideal for students, journalists, or anyone who needs information they can verify. It combines a search engine’s power with the clarity of an AI summary.

ChatGPT: Best AI for Writing and Brainstorming

When it comes to creative writing, productivity, and casual conversation, ChatGPT is still the top performer.

I asked all four AI tools: “Give me 5 ideas for a birthday party for a 10-year-old who loves dinosaurs.”
ChatGPT returned the most imaginative and organized response. It’s great for generating ideas, writing blog posts, drafting emails, or creating social media content.

Plus, it’s easy to use and free to try without signing in.

Google Gemini: Best AI for Gmail and Google Docs

Google Gemini is designed to work seamlessly inside Gmail, Docs, and other Google Workspace apps. It can summarize emails, draft replies, and assist with document writing in real time.

For users who are already in the Google ecosystem, Gemini is a natural choice. Google continues adding features that make it a strong competitor in the AI space.

Microsoft Copilot: Best AI Tool for Excel, Word, and Teams

If you rely on Microsoft Office, Copilot is built just for you. When I gave it an Excel spreadsheet and asked it to “summarize sales trends by region,” it not only analyzed the data but also recommended charts and presentation slides.

Copilot is deeply integrated with Word, Excel, PowerPoint, and Teams, making it the best AI assistant for business users and enterprise environments.

Final Thoughts: Which AI Assistant Should You Use?

Each AI assistant has unique strengths:

  • ChatGPT is best for creative writing and everyday use,
  • Perplexity is best for research with reliable sources,
  • Google Gemini is best for Gmail and Google Docs users,
  • Microsoft Copilot is best for Office and Teams users.

If you’re trying to decide which AI platform to subscribe to in 2025, think about what you use most—Google apps, Microsoft Office, or general productivity. You don’t have to stick with just one. In fact, many people use different tools for different tasks.