They feel different in the hand, and the web versions do not tell you that. ChatGPT app vs Claude app is the best mobile AI assistant question I get, and both are free and excellent, so the choice is about fit, not quality.
The ChatGPT app is the fuller product: voice conversations, image questions, a deeper feature set, the broadest third-party ecosystem. If your phone is your main computer, that depth matters. The Claude app is the calmer product: cleaner interface, genuinely better long-form writing, a feel that stays out of your way. If your phone work is mostly writing and thinking, calm beats depth.
Test them the same way. Dictate a message while walking. Photograph a document and ask questions about it. Ask each to draft something you would actually send. Score accuracy and how much you enjoyed the process. The app you reach for without thinking is the winner, benchmarks aside. This is the best AI tool alternative finder app scenario in miniature: two finalists, one job, pick the fit. A pick my AI stack app free approach says keep both until one clearly loses.
My take: most people end up with the ChatGPT app as the daily driver and the Claude app for writing-heavy days. Two free apps, zero dollars, best of both. Live with both for two weeks, then keep the one your thumb chooses.
I run 210 head-to-head AI tool comparisons with clear verdicts at aitoolguide.fyi. Selling an AI tool? Sponsored placements and affiliate spots put you in front of buyers choosing right now.