Visual CSS border-radius builder with live preview
border-radius: 10px;
The CSS Border Radius Generator by Toolkit Easy is a free, interactive tool that lets you visually create custom border-radius styles for your web projects. Whether you need subtle rounded corners for a button or complex elliptical arcs for a modern card design, this visual border radius builder gives you precise control over every corner of any HTML element.
With support for both pixel (px) and percentage (%) units, the tool handles everything from simple uniform rounding to advanced eight-value border-radius syntax. Each corner — top-left, top-right, bottom-right, and bottom-left — can be configured independently with separate horizontal and vertical radii. The linked checkbox per corner lets you quickly toggle between circular arcs (equal H and V) and elliptical arcs (independent H and V).
The "All Linked" mode synchronizes all four corners to a single value, making it effortless to apply uniform rounding. Shape presets like Square, Rounded, Pill, Circle, Egg, and Leaf give you instant starting points for common design patterns. The live preview updates in real time as you adjust sliders, so you always know exactly what the result will look like.
You can customize the preview box background color, toggle a visible border, and resize the preview dimensions to match your target element. The generated CSS code is displayed and can be copied with one click. This border-radius generator is perfect for front-end developers, UI/UX designers, and anyone building modern, visually appealing websites and applications.
The border-radius CSS property is one of the most frequently used styling tools in modern web development. It transforms rigid, boxy layouts into smooth, organic, and visually appealing interfaces. At its core, border-radius defines the radius of the circle or ellipse used to round the corners of an element. When you set border-radius: 10px, each corner gets a circular rounding with a 10-pixel radius. But the property is far more powerful than a single value suggests.
The border-radius shorthand can accept one to four values for the horizontal radii, and if you include a slash (/), you can specify up to four additional values for the vertical radii. The order follows the standard CSS shorthand pattern: top-left, top-right, bottom-right, bottom-left. For example, border-radius: 10px 20px 30px 40px / 5px 15px 25px 35px sets different horizontal and vertical radii for each corner. This is called the eight-value syntax and it enables highly expressive shapes that go beyond simple rounded rectangles.
When using percentage values, the horizontal radius is calculated as a percentage of the element's width, and the vertical radius as a percentage of its height. This is particularly useful for creating elliptical shapes and organic forms. A border-radius of 50% on a square element creates a perfect circle; on a rectangle it creates an ellipse. By staggering percentage values across corners — such as 50% on top-left and bottom-right, and 20% on top-right and bottom-left — you can achieve pill-like or egg-like shapes that add character to your design.
The concept of linked versus unlinked corners is important for understanding border-radius. When horizontal and vertical radii are equal (linked), the corner forms a circular arc. When they differ (unlinked), the corner forms an elliptical arc, which can create more interesting and dynamic shapes. Most CSS border-radius generators, including ours, provide a way to toggle this per corner, giving you fine-grained creative control.
Practical applications of border-radius are everywhere in modern UI design. Buttons with pill-shaped rounding (50px) are a staple of Material Design and modern frameworks. Card components often use 8px to 16px rounding for a friendly, approachable look. Profile avatars and thumbnails use 50% to create perfect circles. Even complex UI elements like modals, tooltips, and dropdowns benefit from subtle corner rounding that makes them feel polished and intentional.
When combined with other CSS properties like box-shadow, gradients, and background colors, border-radius enables stunning visual effects. The glassmorphism trend relies heavily on border-radius along with backdrop-filter and semi-transparent backgrounds. Neumorphism uses border-radius with inset shadows to create soft, extruded interfaces. Even minimal, flat designs use border-radius to soften the harshness of right angles and improve the overall user experience.
One common misconception is that border-radius clips the content of an element. By itself, border-radius only affects the visual appearance of the border box. To clip the background and content, you need to combine it with overflow: hidden. This is a crucial technique when working with images, gradients, or background patterns inside rounded containers.
Accessibility is another consideration. While rounded corners are generally considered more aesthetically pleasing, they don't typically impact usability. However, be mindful that extreme border-radius values on interactive elements like buttons should maintain a recognizable shape. A button that is too rounded may lose its visual identity as a clickable element. As with all design choices, balance and context are key.
The border-radius generator at Toolkit Easy is designed to be the most intuitive and feature-rich free tool available. With real-time preview, multiple presets, per-corner control, unit switching, and instant CSS output, it streamlines the workflow for designers and developers alike. Whether you are prototyping a new design, fine-tuning a production interface, or learning CSS properties, this visual border radius builder is your go-to resource for all things border-radius.