Jump in free with 60 A/B design challenges, zero credit card required. Two designs. One is better. Can you spot why? SpotTheUI trains your design eye through rapid-fire comparisons across 12 core principles like visual hierarchy, spacing, typography, and color. Four difficulty tiers take you from beginner fundamentals to expert-level details that most designers miss. With 480 challenges total, this isn't a course you watch, it's a gym for your design intuition. Start training your eye today.