Why UX-Driven Companies Prefer Rounded Buttons

In late 2023, I took on the challenge of redesigning the REVE Chat homepage. My goal wasn’t just to create a visually appealing design but to craft an experience that felt seamless and engaging for users. To achieve this, I conducted extensive research to understand what truly distinguishes exceptional designs from the rest.

While exploring 50 top company websites, I noticed a common trend: most used rounded call-to-action (CTA) buttons instead of rectangular ones. This made me curious—were rounded buttons just a style choice, or was there a deeper reason? That question led me on a journey of discovery, testing, and uncovering a fascinating UX principle.

The Journey of Research: Rounded Buttons vs. Rectangles

To find answers, I reflected on familiar design elements. Take the Google search bar, for example—a common browser feature with a rounded shape. It doesn’t rely on flashy colors, yet it stands out prominently on the page. This made me wonder: Do rounded shapes naturally draw more attention in environments dominated by rectangles?

As I analyzed further, I realized that our monitors, browsers, and most interface elements are rectangular. A rounded button or shape creates contrast in such a setting, drawing attention without needing bold colors or extravagant effects. Yet, despite my efforts, I couldn’t find a definitive rule or principle explaining this preference.

A Key Insight from Packaging Design

A breakthrough moment came during an internal design review at REVE Systems. Our GCEO invited me, our Lead UX Designer, and other senior colleagues to evaluate three packaging designs created by Le Delecia’s design team. Two of the designs were nearly identical except for one key difference: one had a circular shape integrated into the design, while the other used a rectangular shape.

To my surprise, all 15 people in the room unanimously preferred the circular design. I understood that the circle naturally drew more attention and looked more aesthetically pleasing, but I still couldn’t name the principle behind it.

Discovering the Von Restorff Effect

The turning point came on my way home one evening. While browsing UX principles, I stumbled upon the Von Restorff Effect, also known as the Isolation Effect. This principle explains that when multiple similar objects are present, the one that differs is most likely to stand out and be remembered.

The theory, introduced by German psychiatrist Hedwig von Restorff in 1933, revealed why the rounded button works so well in environments dominated by rectangular shapes. The button’s contrasting shape isolates it from its surroundings, making it more memorable and attention-grabbing.

What the Von Restorff Effect Teaches Us

The Von Restorff Effect has profound implications for design, particularly in creating standout elements like CTAs. Here are some key takeaways:

1. 1. Make Key Elements Distinctive: Ensure that important actions, like CTA buttons, stand out visually to grab the user’s attention.

1. 1. Use Restraint: Avoid overwhelming users with too many emphasized elements, as this can dilute the impact and lead to confusion.

1. 1. Consider Accessibility: Design elements should not rely solely on color for distinction, as this could exclude users with color vision deficiencies. Rounded buttons, for example, create contrast through shape, making them accessible to a wider audience.

1. 1. Be Mindful of Motion Sensitivity: While motion can highlight differences, it should be used carefully to avoid discomfort for users with motion sensitivity.

Applying the Principle to Rounded Buttons

This principle clarified why rounded buttons are favored by top companies. The contrast created by their shape makes them distinct and ensures that users notice them, even if they have color blindness or other visual impairments. Rounded buttons don’t just look good—they improve usability and accessibility, aligning perfectly with the goals of user-centered design.

Conclusion: Research Unlocks Better Design

My journey to improve REVE Chat’s homepage design underscored the importance of research and curiosity in solving design challenges. By studying top companies, observing patterns, and digging into UX principles like the Von Restorff Effect, I learned how small design choices—like using rounded buttons—can significantly impact user experience.

This experience taught me that every detail in design has a reason and that understanding these reasons can elevate the quality of your work. Rounded buttons aren’t just a trend—they’re a smart application of psychological principles that help create designs that are both functional and beautiful.