SpotTheUI

SpotTheUI offers an interactive way to improve visual design judgment by presenting users with pairs of UI mockups and asking them to choose the one that better follows a specific design principle. Each challenge includes a concise explanation of why the selected design is superior, covering twelve core principles such as contrast, alignment, balance, hierarchy, white space, repetition, proximity, unity, rhythm, and typography. The platform provides four difficulty levels, allowing beginners to start with obvious differences and progress to subtler distinctions.

The tool targets anyone looking to sharpen their design sense, including design students, developers, self‑taught designers, and junior professionals. It emphasizes hands‑on practice over theoretical content, delivering rapid, 30‑second exercises that aim to build intuition through repeated exposure to real design decisions.

With 480 hand‑crafted challenges, users can track progress via experience points, levels, and badges, while the free tier offers sixty challenges and a paid option unlocks the full set. The experience is presented as a simple, fast, and gamified “design gym” for the eyes.