UI Critic by Usercall is an AI-powered tool that provides synthetic user testing feedback on design screenshots. Users can upload 1-3 screenshots of their product, design, or mockups to receive annotated critiques that identify hidden assumptions and potential risks.

The tool generates annotated design critiques with pinned annotations across screenshots. It provides user feedback from synthetic or simulated users, helping designers understand how their designs might be perceived. The system analyzes UI screenshots to surface assumptions that designers may have made unconsciously.

Users simply upload their screenshots and receive detailed feedback highlighting potential issues and assumptions. The annotations are pinned directly to specific areas of the screenshots, making it easy to understand which design elements need attention.

The primary benefit is identifying hidden user assumptions and risks before shipping designs, potentially saving time and resources. This helps designers catch issues early in the design process when changes are easier and less costly to implement.

The tool targets designers and product teams working on user interfaces who need quick feedback on their designs without conducting full user testing sessions.