W3cubDocs

/CSS

border-top-left-radius

The border-top-left-radius CSS property rounds the top-left corner of an element.

The rounding can be a circle or an ellipse, or if one of the value is 0,no rounding is done and the corner is square.

A background, being an image or a color, is clipped at the border, even a rounded one; the exact location of the clipping is defined by the value of the background-clip property.

If the value of this property is not set in a border-radius shorthand property that is applied to the element after the border-top-left-radius CSS property, the value of this property is then reset to its initial value by the shorthand property.

Syntax

/* the corner is a circle */
/* border-top-left-radius: radius */
border-top-left-radius: 3px;

/* the corner is an ellipse */
/* border-top-left-radius: horizontal vertical */
border-top-left-radius: 0.5em 1em;

border-top-left-radius: inherit;

With one value:

the value is a <length> or a <percentage> denoting the radius of the circle to use for the border in that corner.

With two values:

the first value is a <length> or a <percentage> denoting the horizontal semi-major axis of the ellipse to use for the border in that corner.
the second value is a <length> or a <percentage> denoting the vertical semi-major axis of the ellipse to use for the border in that corner.

Values

<length-percentage>: Denotes the size of the circle radius or the semi-major and semi-minor axes of the ellipse. As absolute length it can be expressed in any unit allowed by the CSS <length> data type. Percentages for the horizontal axis refer to the width of the box, percentages for the vertical axis refer to the height of the box. Negative values are invalid.

Formal syntax

<length-percentage>{1,2}where 
<length-percentage> = <length> | <percentage>

Examples

Live example	Code
	An arc of ellipse is used as the border div { border-top-left-radius: 40px 40px; }
	An arc of ellipse is used as the border div { border-top-left-radius: 40px 20px; }
	The box is a square: an arc of circle is used as the border div { border-top-left-radius: 40%; }
	The box is not a square: an arc of ellipse is used as the border div { border-top-left-radius: 40%; }
	The background color is clipped at the border div { border-top-left-radius:40%; border-style: black 3px double; background-color: rgb(250,20,70); background-clip: content-box; }

Specifications

Specification	Status	Comment
CSS Backgrounds and Borders Module Level 3 The definition of 'border-top-left-radius' in that specification.	Candidate Recommendation	Initial definition

Initial value	`0`
Applies to	all elements; but User Agents are not required to apply to `table` and `inline-table` elements when `border-collapse` is `collapse`. The behavior on internal table elements is undefined for the moment.. It also applies to `::first-letter`.
Inherited	no
Percentages	refer to the corresponding dimension of the border box
Media	visual
Computed value	two absolute `<length>`s or `<percentage>`s
Animation type	a length, percentage or calc();
Canonical order	the unique non-ambiguous order defined by the formal grammar

Browser compatibilityUpdate compatibility data on GitHub

	Desktop
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic support	4 4 1 Prefixed Prefixed Requires the vendor prefix: -webkit-	12 12 12 Prefixed Prefixed Requires the vendor prefix: -webkit-	4 4 Prior to Firefox 50, border styles of rounded corners were always rendered as if `border-style` was solid. This has been fixed in Firefox 50. 49 Prefixed Prefixed Requires the vendor prefix: -webkit- 44 Prefixed Disabled Prefixed Requires the vendor prefix: -webkit- Disabled From version 44: this feature is behind the `layout.css.prefixes.webkit` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config. 1 — 12 Uses the non-standard name: `-moz-border-radius-topleft`	9	10.5	5 5 3 Prefixed Prefixed Requires the vendor prefix: -webkit-
Percentages	4	12	4 4 1 Before Firefox 4, the `<percentage>` was relative to the width of the box even when specifying the radius for a height. This implied that `-moz-border-radius-topleft` was always drawing an arc of circle, and never an ellipse, when followed by a single value.	9	10.5	5
Ellipitcal corners	1	12	3.5	9	10.5	3

	Mobile
	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	iOS Safari	Samsung Internet
Basic support	?	?	Yes Yes Yes Prefixed Prefixed Requires the vendor prefix: -webkit-	Yes Yes Prior to Firefox 50, border styles of rounded corners were always rendered as if `border-style` was solid. This has been fixed in Firefox 50.	?	?	?
Percentages	?	?	Yes	Yes	?	?	?
Ellipitcal corners	?	?	Yes	Yes	?	?	?