CSS Border Radius Generator - Visual Corner Rounder
286 uses20px
20px
20px
20px
Tips
Circle
Set 50% for a perfect circle
Link
Link corners to adjust all at once
Organic
Different values per corner for blob shapes
Units
px for fixed, % for responsive
Frequently Asked Questions
How do I implement the generated CSS border-radius code into my HTML or stylesheet?
After customizing your border-radius visually, simply copy the complete CSS code provided by the generator. Paste it into your project's stylesheet (e.g., `style.css`) or directly within a `<style>` tag in your HTML `<head>`. Ensure you target the correct HTML element using its class or ID selector to apply the desired rounded corners effectively. This streamlines design and ensures correct syntax.
What happens if I set a border-radius value higher than half of the element's width or height using this generator?
When you set a `border-radius` value exceeding half of the shortest side of an element, the actual visual curve will cap at 50% of that side. The browser automatically limits the radius to prevent overlapping curves or malformed shapes. For example, on a 100x100px square, setting `border-radius: 200px;` will still result in a perfect circle, as if you had set `50px` or `50%`, effectively preventing an overly large radius.
What does the 'unlink' button do?
Clicking the 'unlink' button disconnects the individual corner controls. This means you can adjust one corner's radius without affecting the others. You'll see the four input fields become independent. It's handy for creating asymmetrical designs.
Can I use percentage values instead of pixels?
Yes, you can switch between pixels and percentages in the generator. Percentages are relative to the element's dimensions, not the radius itself. A 50% value on a 200px-wide box creates a 100px radius at the corners. This matters most for responsive layouts where element size changes. Try using percentages when your design needs to scale fluidly across screens.
Why does my border-radius look different on mobile?
If you used pixel values, the radius stays fixed regardless of screen size. On a phone, a 40px radius looks massive compared to a desktop. Switch to percentage values — they scale with the element. For example, 10% stays proportional whether your button is 150px or 300px wide. Test your design in the generator's responsive preview mode first.
Can I export the border-radius as a CSS variable or custom property?
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.
Does border-radius affect performance on slow devices?
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.
Is there a keyboard shortcut to reset all corners?
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.
Does border-radius turn a square into an actual circle?
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.
I've seen designs where only two opposite corners are rounded, like a leaf shape. How do I set different values for each corner without messing up the others?
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.
How to Use
- Toggle link mode
- Adjust corner sliders
- Preview shape
- Copy CSS