Poly Duo

About

Any AI can sound sure and still be wrong. Poly Duo sends your question to ChatGPT, then Claude answers the same question on its own, without seeing the first reply, and compares the two. In about a minute you get three blocks: where they agree, where they differ, and what is worth checking yourself. On iPhone it is an Apple Shortcut built on the official actions of the ChatGPT and Claude apps: start it from the Action Button, Siri or Back Tap. Free accounts are enough, nothing passes through our server, and the code is open on GitHub (github.com/vadimchernets/poly-duo). On Android, Poly Duo is inside the Poly app on Google Play and uses two free AI models. In a test on 100 newly written questions (GPT-6.1 Sol and Claude Opus 5.5, October 2026) the two models agreed 74 times and were right in 72 of those. The other 26 are exactly where a second look matters. Built by Vadym Chernets, AI researcher (NeurIPS 2026).