CSS Border Radius Generator - Visual Corner Rounder

A This generator outputs standard CSS properties, not custom properties like `--radius: 20px`. You'd need to manually wrap the output in a `var()` call inside your stylesheet. For example, paste the code into your CSS, then replace the value with `var(--my-radius)`. The generator is designed for quick visual tweaks—if you need CSS variables, copy the values over yourself. It takes about 30 seconds.

A Rounded corners use GPU acceleration in modern browsers, so they're actually faster to render than complex shadows or gradients. But stacking dozens of elements with border-radius on an old phone will drain battery. I've seen freelance devs put 50+ rounded cards on a single page — that's when you notice lag. Stick to under 30 elements with radius values under 20px for budget Android devices. Test on a 2019 Moto G to be safe.

A Nope, no keyboard shortcut for that. You'll need to click the reset button or manually set each corner back to 0. I've seen freelancers waste 10 minutes tweaking corners they meant to reset — just hit the reset icon in the top-right corner. It clears every input field instantly.

A Only if the element is a perfect square and you set all corners to 50%. On a 200x200px box, border-radius: 50% creates a true circle. But on a 300x200px rectangle, 50% gives you an oval — the horizontal and vertical radii differ. The generator shows this live, so drag a corner slider on a rectangular box. You'll see it morph into a pill shape when all four corners hit 50%. That's not a bug; it's how CSS math works.

A That's exactly what the unlink button is for. Click it to break the four corners apart, then set top-left and bottom-right to your desired radius while keeping the other two at 0. For a leaf effect on a 120px-wide button, try 60px on those diagonal corners. You'll get a smooth teardrop outline. The preview updates instantly, so fiddle with the sliders until the shape feels organic. If you ever get lost, the reset icon brings everything back to zero.

A Older Firefox versions had a bug where sub-pixel rounding made curves look jagged, especially under 4px radii. Chrome renders those same values with smoother anti-aliasing. Your generated code isn't wrong — the browser's rendering engine differs. Test with at least a 6px radius to hide the discrepancy, and add `-moz-border-radius` only if you're stuck supporting Firefox ESR 102. For modern browsers, the standard `border-radius` property handles everything correctly. I check my output in both browsers before shipping, and you should too, if the design is client-facing.

A Not at all. You can build organic shapes by mixing percentages, pixels, and unlinked corners. A 100px element with top-left at 100%, top-right at 20px, and bottom corners at 0 creates a skewed blob. Export the code and pair it with clip-path if you need concave curves. Try the preset sliders first, they're faster than hand-coding. Most devs underuse this: check how borders with different widths react to radius, you'll get layered effects.

A Yes, you can animate border-radius changes when hovering over buttons or cards. Add a transition duration like 0.3s ease to your generated CSS code. When a user hovers over the element, the corners morph seamlessly from square to round. Just make sure the starting and ending units match. Animating from pixels to percentages can cause a jarring jump mid-animation.

A Code from this generator only styles the container box, so any direct child image will overflow unless you add overflow hidden. I learned this the hard way on a portfolio site last week. Drop `overflow: hidden` right below your border-radius property in your CSS file. That forces the image to clip neatly inside the curved edges without any messy awkward bleed. Try previewing it with a sample photo to confirm the crop looks sharp.

A Browsers actually reject negative values entirely for this property. If you try typing minus 20 pixels into the CSS, the browser simply treats it as zero. But you can still create inverted or concave shapes using SVG masks or the CSS clip-path property instead. This generator focuses strictly on standard convex radius curves. Dragging a slider below zero won't break the tool, but the output code stays safe at zero.