TL;DR: There's no single winner. Claude is excellent for nuanced writing, reasoning, and long-context critique; Gemini is strongest for multimodal, image-heavy tasks; ChatGPT is a versatile all-rounder with a deep tool ecosystem. The best designers don't pick one — they route each task to the tool that's best at it.

Which AI tool is best for product design?

The honest answer is “it depends on the task.” All three are capable assistants, but they have different strengths. Treat them like specialists on your team rather than a single oracle.

When should you use Claude?

Claude (from Anthropic) is my default for anything language- and judgment-heavy: rewriting UX copy with a consistent voice, critiquing a flow against heuristics, summarizing long research transcripts, and reasoning carefully through tradeoffs. Its strength is thoughtful, well-structured output over long context.

When should you use Gemini?

Gemini (from Google) shines on multimodal work. Hand it a screenshot or mockup and it will reason about visual hierarchy, contrast, and accessibility. If your task starts with an image rather than text, reach for Gemini first.

When should you use ChatGPT?

ChatGPT (from OpenAI) is the flexible generalist — strong at brainstorming, structured drafting, and quick iteration, with a broad ecosystem of integrations. It's a reliable first stop when you're not sure which tool fits.

How I combine all three

In practice I use Gemini to analyze a screen, Claude to refine the copy and pressure-test the logic, and ChatGPT to brainstorm directions when I'm stuck. The meta-skill isn't loyalty to one tool — it's knowing which one to reach for, and always treating the output as a draft you improve with your own taste.

FAQ

Which AI is best for UX writing? Claude tends to produce the most natural, on-voice copy, but all three are usable — give them clear context and ask for options.

Which is best for analyzing screenshots? Gemini, thanks to its strong multimodal understanding.

Do I need to pay for all three? No. Start with one, add another only when you hit a task it's weak at.

Carlos Lastres is an Apple Design Award–winning product designer and software engineer based in Tokyo who works hands-on with AI tools to design conversion-focused products.