Free CSS Border Radius Generator

The Complete Guide to CSS Border Radius

Border radius is a fundamental CSS property that transforms sharp, rectangular corners into smooth, rounded curves. Our free CSS border radius generator provides an intuitive visual interface for creating perfect rounded corners with precise control over each corner individually. Whether you're designing modern cards, circular avatars, pill-shaped buttons, or organic custom shapes, this tool generates production-ready CSS code with live preview for immediate visual feedback.

The border-radius property supports both pixel values for consistent sizing across screen sizes and percentage values for responsive shapes like circles. You can control all four corners simultaneously for symmetrical designs or adjust each corner independently for unique, organic shapes. Our generator includes 16 preset shapes covering common design patterns from subtle rounded corners to perfect circles, pill shapes, and creative leaf and teardrop forms.

Understanding CSS Border Radius

Border Radius Syntax

The CSS border-radius property accepts values from 0 (square corners) to any positive value. Basic syntax: border-radius: 8px; rounds all four corners equally. For individual corners: border-radius: 8px 16px 8px 16px; where values apply to top-left, top-right, bottom-right, and bottom-left in that order.

The property also supports shorthand: two values (8px 16px) apply to top-left/bottom-right and top-right/bottom-left. Three values apply to top-left, both sides, and bottom-right. Our tool generates the most efficient CSS syntax based on your corner values. For more CSS utilities, check our CSS Beautifier.

Pixel Values vs Percentage Values

Pixel values (px) create consistent border radius regardless of element size. An 8px border radius always curves the same amount, perfect for buttons, cards, and most UI elements. Pixels provide predictable results and work well for fixed designs. Use pixels when you want the same visual rounding across different element sizes – a small button and large card both get the same corner curve with 8px.

Percentage values (%) are relative to the element's dimensions. A 50% border radius creates a perfect circle on square elements (width equals height). Percentages are essential for responsive circular avatars, profile pictures, and shapes that should maintain proportions as they scale. Use 50% for circles and 10-20% for proportional rounding on cards. Percentages adapt to element size automatically, making them ideal for responsive designs.

Individual Corner Properties

Beyond the shorthand, CSS provides individual corner properties: border-top-left-radius, border-top-right-radius, border-bottom-right-radius, and border-bottom-left-radius. These are useful when you need to dynamically adjust specific corners, override inherited values, or create responsive designs where certain corners change at breakpoints. Our tool generates shorthand by default for cleaner code, but individual properties provide more flexibility for complex scenarios.

Common Border Radius Use Cases

Rounded Buttons

Buttons benefit from subtle border radius (4-8px) for approachability without overwhelming the design. Our "Slight" and "Rounded" presets work perfectly for most buttons. For pill-shaped buttons popular in modern design, use a very large value like 999px or our "Pill" preset – this fully rounds the short sides regardless of button width. Pill buttons are ideal for CTAs, tags, and navbar items. Avoid perfectly circular buttons for text labels as they waste space and look awkward with variable text lengths.

Card Components

Card border radius creates visual separation from backgrounds and adds polish. Standard card radius ranges from 8px (subtle) to 16px (pronounced). Larger cards can handle more rounding (24-32px) without looking odd. Our "Rounded" and "Large" presets cover most card needs. For card headers or footers with distinct backgrounds, consider rounding only specific corners: top corners for headers (border-radius: 8px 8px 0 0;) or bottom corners for footers. This technique, available in our "Top Rounded" and "Bottom Rounded" presets, creates seamless visual flow.

Circular Avatars and Profile Pictures

Perfect circles require border-radius: 50%; on square elements (equal width and height). This is the standard for user avatars, profile pictures, and icon containers. Our "Circle" preset applies this automatically. The 50% value works because each corner's curve extends halfway across both dimensions, meeting at the center to form a complete circle. For non-square elements, 50% creates an ellipse. Ensure your image containers are square (use aspect-ratio: 1; or equal width/height) for true circles. Combine with object-fit: cover; for images that fill the circle properly.

Input Fields and Forms

Form elements use subtle border radius (4-6px) for modern appearance while maintaining clear boundaries. Too much rounding on inputs looks unprofessional and suggests buttons rather than text fields. Our "Slight" preset works well for most form controls. For search bars and filter inputs, slightly more rounding (8px) or pill shapes create a distinct appearance. Match button and input border radius within forms for visual cohesion. Dropdown selects, textareas, and checkboxes should share the same radius value as text inputs for consistency.

Modals and Dialogs

Modal windows typically use medium border radius (12-16px) to differentiate from page content and create focus. Larger modals (full-screen on mobile, large desktop dialogs) can handle more pronounced rounding without looking awkward. Small modals (alerts, confirmations) work better with subtle rounding to maximize content space. Our "Large" preset provides good starting point for modals. Consider rounding only top corners on mobile modals that slide up from bottom, creating a sheet-like appearance popular in mobile design. This technique, using our "Top Rounded" preset, suggests the modal can be dismissed by pulling down.

Images and Media

Rounded images soften harsh rectangular boundaries. Product photos often use 8-16px radius for modern e-commerce aesthetics. Hero images and banners use subtle rounding (4-8px) to avoid distracting from content. Thumbnails in galleries benefit from consistent small radius (4-6px) for cohesive grid appearance. For portrait photos in testimonials or team pages, circular crops (50% radius) or leaf shapes create visual interest. Use our preset library to explore creative shapes like "Teardrop" and "Organic" for unique image treatments. Ensure parent containers have overflow: hidden; to clip images to the border radius shape.

Creative Border Radius Techniques

Asymmetrical Corners for Unique Shapes

Individual corner control creates distinctive, organic shapes. Our "Leaf" presets demonstrate single-corner rounding – perfect for speech bubbles, callouts, and design accents. Diagonal opposite corners (top-left and bottom-right, or top-right and bottom-left) create dynamic, modern shapes popular in hero sections and feature cards. Try our "Diagonal" preset for this effect. Varying corner values subtly (40%, 60%, 40%, 60%) creates natural, organic shapes without perfect symmetry, great for testimonial cards and artistic layouts. Experiment with our "Organic" preset or use individual corner controls for custom combinations.

Elliptical Border Radius

Border radius supports elliptical curves with two values per corner: horizontal radius / vertical radius. Syntax: border-radius: 50px / 30px; creates an ellipse. For individual corners: border-top-left-radius: 50px 30px; where the first value is horizontal curve and second is vertical. This creates more dramatic, organic shapes than standard circular curves. Useful for unique button styles, decorative elements, and custom blob shapes. While our tool focuses on standard border radius, you can take the generated code and manually add the slash notation for elliptical effects.

Notched Corners

While border-radius creates curves, combining it with clip-path creates notched or cut corners. For pure CSS notches without clip-path, use nested elements: a container with background and padding, inner element with different background and matching border radius. The gap appears as a notch. Another technique: use conic gradients with border radius for complex corner treatments. These advanced techniques go beyond simple border radius but show how the property integrates with other CSS features for creative effects. Check our Gradient Generator for gradient-based designs.

Animated Border Radius

Border radius can be animated smoothly with CSS transitions: transition: border-radius 0.3s ease; Popular patterns include cards that become more rounded on hover, buttons that morph from rectangles to pills, and shapes that shift organically. For continuous animation, use CSS keyframes to cycle through different radius values, creating blob-like morphing effects. Animated radius changes feel organic and playful, perfect for interactive elements, loading states, and creative hero sections. Keep animations subtle (small radius changes) for professional interfaces, or dramatic for artistic sites. Performance is excellent as border-radius is GPU-accelerated.

Border Radius Best Practices

Consistency Across Components

Establish a border radius scale in your design system: 0px (none), 4px (slight), 8px (medium), 16px (large), 32px (extra-large), 50% (circle). Use these values consistently across all UI elements. Buttons, cards, inputs, and images within the same interface should share radius values to create cohesion. Define these as CSS custom properties: --radius-sm: 4px; --radius-md: 8px; etc. This systematic approach ensures consistency and makes updates easy – change the custom property value and all instances update automatically.

Scale Border Radius with Element Size

Larger elements can handle more border radius without looking odd. A small button with 16px radius looks nearly circular, while a large card with 16px radius looks subtly rounded. Match radius to size: small elements (buttons, chips) use 4-8px, medium elements (cards, modals) use 8-16px, large elements (hero sections, full-width containers) use 16-32px. For responsive designs, consider using percentage values or CSS clamp(): border-radius: clamp(8px, 2vw, 24px); scales radius with viewport width, maintaining proportions across screen sizes.

Avoid Over-Rounding

Too much border radius creates awkward shapes and wastes space. Text containers (paragraphs, headings) should rarely have border radius beyond 8px as excessive rounding interferes with text flow and readability. Navigation items, form labels, and table cells benefit from subtle rounding (4-6px) or none at all for clarity. Reserve dramatic rounding (32px+) and circles (50%) for specific purposes: large buttons, avatars, decorative elements. When in doubt, start subtle – you can always increase radius, but over-rounded designs look unprofessional and dated.

Consider Padding and Content

Border radius interacts with padding and content placement. Elements with large radius need sufficient padding to prevent content from touching rounded corners, which looks cramped. Rule of thumb: padding should be at least half the border radius value. For example, 16px radius needs 8px+ padding. Icons and text near corners should have extra margin to respect the curve. For circular elements, center content carefully – off-center content breaks the circular illusion. Test border radius with actual content during design, not just empty boxes, to ensure proper spacing.

Performance and Browser Support

Border Radius Performance

Border radius has excellent performance in modern browsers with GPU acceleration. It doesn't trigger layout reflow, making it safe to animate. Rounded corners render efficiently even with large radius values and don't impact page speed. Unlike image-based rounded corners used in the past, CSS border radius requires no HTTP requests, works at any resolution, and scales perfectly on retina displays. Complex shapes with many elements using different radius values have negligible performance impact. Border radius is one of the most performant CSS visual properties available.

Browser Compatibility

Border radius has universal browser support – all modern browsers including Chrome, Firefox, Safari, Edge, and mobile browsers fully support the property. Very old browsers (IE8 and below) don't support border-radius, but these browsers are essentially extinct in 2025. No vendor prefixes are needed with modern CSS. The syntax our tool generates works everywhere without compatibility concerns. Elliptical border radius (two values per corner) also has full support. You can confidently use border radius without fallbacks or workarounds. Use our CSS Minifier to optimize your border radius code.

Mobile and Touch Interfaces

Border radius is particularly important on mobile interfaces where rounded corners feel more natural for touch interactions. Mobile OS design languages (iOS, Android) heavily feature rounded corners, so web designs that match these conventions feel native. Buttons with border radius appear more tappable than sharp rectangles. Consider slightly increasing border radius on mobile breakpoints for improved touch ergonomics – larger tap targets benefit from more pronounced rounding. Test on actual devices to ensure radius looks appropriate at different screen densities. High-DPI screens render border radius crisp and smooth.

Design Trends and Border Radius

Modern Design Aesthetics

Current design trends favor generous border radius for friendly, approachable interfaces. Material Design 3 increased default radius values compared to Material Design 2. Glassmorphism, neumorphism, and modern card-based layouts rely heavily on border radius for their soft, rounded aesthetic. Tech companies like Apple and Google showcase bold border radius in their design systems. Minimalist designs use subtle radius (4-8px) for refinement without distraction, while playful, consumer-facing brands use dramatic rounding (24px+) and organic shapes for personality and warmth.

When to Use Sharp Corners

Not everything needs rounding. Sharp corners (border-radius: 0) convey professionalism, precision, and formality. Financial applications, legal sites, and enterprise dashboards often use minimal rounding for serious, business-like appearance. Tables, spreadsheets, and data grids benefit from sharp corners for clear cell boundaries. Text-heavy layouts (documentation, articles, wikis) use minimal radius to maximize reading area and minimize distraction. Brutalist and editorial designs intentionally avoid border radius for raw, unpolished aesthetics. Know when rounding serves your design goals versus when sharp corners are more appropriate.

Frequently Asked Questions