What is Border Radius Generator?
A border radius generator creates CSS border-radius values with per-corner control. This tool gives independent sliders for top-left, top-right, bottom-right, and bottom-left, previews the shape, and copies either a single value when all corners match or the four-value shorthand tl tr br bl.
All lengths are emitted in pixels. Elliptical radii (the slash syntax) are not generated.
CSS border-radius accepts one to four values before optional elliptical slash syntax. This generator covers the everyday one- and four-value pixel cases that design systems use for cards, inputs, and images.
Why Use This Tool?
Asymmetric radii are common in modern cards and media frames. Editing four corners visually is clearer than memorizing shorthand order.
Copying the exact shorthand prevents mistakes like confusing TR/BR when translating from design tools.
Corner radius is one of the strongest brand shape signals. Generating the shorthand correctly avoids asymmetric bugs when only one corner should stay sharp.
- Four independent corner controls
- Live shape preview
- Smart shorthand when corners are equal
- Copy-ready CSS
How Does This Tool Work?
If tl === tr === br === bl, output is Npx. Otherwise output is TLpx TRpx BRpx BLpx in that order—the standard CSS four-value border-radius shorthand.
Move any slider to update the preview silhouette and the CSS string. Equalizing all four corners collapses output to a single length automatically.
Understanding Your Results
Larger values round more aggressively; when radius exceeds half of a side, the corner visually caps based on the box size in CSS layout.
Preview size is illustrative—the same radius looks different on a 40px chip versus a 400px card.
A 999px radius on a short button creates a pill. On a tall card, the same number only rounds corners—pill behavior depends on box geometry, not the generator alone.
Why Tracking This Matters
Consistent radii are a core design-system signal. Shipping one token string keeps components aligned.
Shared radius tokens (--radius-sm, --radius-lg) reduce one-off rounded corners that make interfaces feel inconsistent.
Benefits of Using Border Radius Generator
- No shorthand order mistakes
- Instant preview
- Equal-corner compression to one value
- Simple px output for tokens
- Private local tool
- Free to use
How Is the Result Calculated?
borderRadiusCss compares the four inputs and formats the minimal correct shorthand.
The tool does not clamp radii to element size; CSS rendering handles how oversized radii resolve against the border box.
Npx | TLpx TRpx BRpx BLpx
- TL, TR, BR, BL
- Corner radii in pixels, clockwise from top-left.
Tips for Better Results
- Match radii across buttons, inputs, and cards for a cohesive UI.
- Use fully rounded pills with a large radius on short controls, not on every container.
- Store the copied value in a CSS variable like --radius-md.
- Remember 50% circles need equal width/height—px radii alone do not create ellipses.
- Check clipped content (overflow: hidden) when large radii meet images.
- Use smaller radii on dense data UI and larger radii on marketing surfaces—document the rule in your design system.
Standards and References
Conclusion
Adjust each corner until the preview matches your intent, copy the border-radius value, and reuse it as a design token across components.
Decide which corners carry brand character, copy the shorthand, and reuse it across components so shape language stays consistent.