IE9 border-radius and background gradient bleeding

Problem

IE9 is apparently able to handle rounded corners by using the CSS3 standard definition of border-radius.

What about support for border radius and background gradient? Yes IE9 is to support them both separately, but if you mix the two the gradient bleeds out of the rounded corner.

I am also seeing strangeness with shadows showing as a solid black line under a box with rounded corners.

Here are the images shown in IE9:

image with no bleed, but sharp corners image with bleed

How can I work around this problem?

Problem courtesy of: SigmaBetaTooth

Solution

Here's one solution that adds a background gradient, using a data URI to create a semi-transparent image that overlays any background color. I've verified that it's clipped correctly to the border radius in IE9. This is lighter weight than SVG-based proposals but as a downside, is not resolution-independent. Another advantage: works with your current HTML/CSS and does not require wrapping with additional elements.

I grabbed a random 20x20 gradient PNG via a web search, and converted it into a data URI using an online tool. The resulting data URI is smaller than the CSS code for all that SVG mess, much less the SVG itself! (You could apply this conditionally to IE9 only using conditional styles, browser-specific css classes, etc.) Of course, generating a PNG works great for button-sized gradients, but not page-sized gradients!

HTML:

<span class="button">This is a button</span>

CSS:

span.button { 
  padding: 5px 10px;
  border-radius: 10px;
  background-color: orange;  
  background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAAvUlEQVQ4y63VMQrDMAyF4d/BGJ+rhA4dOnTo0Kn3P4ExxnSoXVQhpx0kEMmSjyfiKAF4AhVoqrvqjXdtoqPoBMQAPAZwhMpaYkAKwH1gFtgG0v9IlyZ4E2BVabtKeZhuglegKKyqsWXFVboJXgZQfqSUCZOFATkAZwEVY/ymQAtKQJ4Jd4VZqARnuqyxmXAfiAQtFJEuG9dPwtMC0zD6YXH/ldAddB/Z/aW4Hxv3g+3+6bkvB/f15b5gXX8BL0z+tEEtuNA8AAAAAElFTkSuQmCC);
  background-size: 100% 100%;

  border: 2px solid white;
  color: white;
}
Solution courtesy of: Steve Eisner

Discussion

I also got stuck in the same problem n found that IE can't render the border radius and gradient both at a time, it both conflicts, the only way to solve this headache is to remove the filter and use the gradient via svg code, just for IE ..

you can get the svg code by using their gradient color code, from Microsoft this site (specially made for gradient to svg):

http://ie.microsoft.com/testdrive/graphics/svggradientbackgroundmaker/default.html

enjoy :)

Discussion courtesy of: Himanshu Jani

IE9 handles border-radius and gradients together properly. The problem is that IE9 renders the filter proper in addition to the gradient. The way to properly solve this is to disable filters on the style declarations that utilize the filter property.

As an example on how to best solve this:

You have a button class in your main stylesheet.

.btn {
    background: linear-gradient(to bottom,  #1e5799 0%,#7db9e8 100%);
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#1e5799', endColorstr='#7db9e8',GradientType=0 );
}

In a conditional IE9 stylesheet:

.btn { filter: none; }

As long as the IE9 stylesheet is referenced in your head after your main stylesheet this will work perfectly.

Discussion courtesy of: WFendler

The mask div in IE9 is a good idea. I am supplying some complete code to help clarify a bit. While I am not happy with wrapping the button in a DIV, I think it's easier to understand than embedding a PNG mask or going through all the effort using SVG. Maybe IE 10 will support it properly.

<!DOCTYPE html>
<html>
<head>
<title>Button Test</title>
<style>
.btn_mask { cursor:pointer;padding:5px 10px;border-radius:11px 11px 11px 11px;
 background-color:transparent;-moz-border-radius:11px 11px 11px 11px;
 -webkit-border-radius:11px 11px 11px 11px;overflow:hidden;padding:0px;
 float:left; }
.btn { cursor:pointer;text-decoration:none;border:1px solid rgb(153,153,153);
 padding:5px 10px;color:rgb(0,0,0);font-size:14px;font-family:arial,serif;
 text-shadow:0px 0px 5px rgb(255,255,255);font-size:14px;
 border-radius:11px 11px 11px 11px;-moz-border-radius:11px 11px 11px 11px;
 -webkit-border-radius:11px 11px 11px 11px;box-shadow:0px 0px 0px rgb(0,0,0);
 -moz-box-shadow:0px 0px 0px rgb(0,0,0);
 -webkit-box-shadow:0px 0px 0px rgb(0,0,0);background-color:rgb(255,204,0);
 background-image:linear-gradient(-90deg,rgb(255,255,153),rgb(255,204,0));
 background-image:-webkit-gradient(linear,50% 0%,50% 100%,from(rgb(255,255,153)),to(rgb(255,204,0)));-ms-filter:"progid:DXImageTransform.Microsoft.gradient(startColorStr='#ffffff', EndColorStr='#ffcc00)')";background-image:-moz-linear-gradient(-90deg,rgb(255,255,153),rgb(255,204,0));
}
.btn:hover { cursor:pointer;text-decoration:none; border:1px solid rgb(153,153,153); padding:5px 10px 5px 10px; color:rgb(0,0,0); font-size:14px; font-family:arial,serif; text-shadow:0px 0px 5px rgb(255,255,255); font-size:14px; border-radius:11px 11px 11px 11px; -moz-border-radius:11px 11px 11px 11px; -webkit-border-radius:11px 11px 11px 11px; box-shadow:0px 0px 0px rgb(0,0,0); -moz-box-shadow:0px 0px 0px rgb(0,0,0); -webkit-box-shadow:0px 0px 0px rgb(0,0,0); background-color:rgb(255,255,0); background-image:linear-gradient(-90deg,rgb(255,255,0),rgb(255,255,153)); background-image:-webkit-gradient(linear,50% 0%,50% 100%,from(rgb(255,255,0)),to(rgb(255,255,153))); background-image:-moz-linear-gradient(-90deg,rgb(255,255,0),rgb(255,255,153)); }
</style>
</head>
<body>
<form name='form1'>
<div class='btn_mask'><input type='button' class='btn' value='a button'></div>
<div class='btn_mask'><input type='button' class='btn' value='a button'></div>
<div class='btn_mask'><input type='button' class='btn' value='a button'></div>
<div class='btn_mask'><input type='button' class='btn' value='a button'></div>
</form>
</body>
</html>
Discussion courtesy of: underdog

I have also been working with this problem. Another "solution" is to add a div around the item that has the gradient and rounded corners. Make that div the same height, width, and rounded corner values. Set the overflow to hidden. This is basically just a mask, but it works for me.

HTML:

<div class="mask roundedCorners">
    <div class="roundedCorners gradient">
        Content
    </div>
</div>

CSS:

.mask
{
    overflow: hidden;
}

.roundedCorners
{
    border-radius: 5px;
    -moz-border-radius: 5px;
    -webkit-border-radius: 5px;
}

.gradient
{
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#0065a4', endColorstr='#a0cf67',GradientType=0 ); /* IE6-9 */
}
Discussion courtesy of: user740128

I decided to disable IE9 from rounding corners to workaround this bug. It's clean, easy and generic usable.

{
border-radius:10px;
border-radius:0px \0/;
background:linear-gradient(top , #ffeecc, #ff8800);
/* ... (-moz -ms,-o, -webkit) gradients */    
filter: progid:DXImageTransform.Microsoft.gradient(GradientType=0,startColorstr=#ffeecc,endColorstr=#ff8800);
}
Discussion courtesy of: key_
background: #4f81bd; /* Old browsers */
/* IE9 SVG, needs conditional override of 'filter' to 'none' */
background: url(data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiA/Pgo8c3ZnIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgd2lkdGg9IjEwMCUiIGhlaWdodD0iMTAwJSIgdmlld0JveD0iMCAwIDEgMSIgcHJlc2VydmVBc3BlY3RSYXRpbz0ibm9uZSI+CiAgPGxpbmVhckdyYWRpZW50IGlkPSJncmFkLXVjZ2ctZ2VuZXJhdGVkIiBncmFkaWVudFVuaXRzPSJ1c2VyU3BhY2VPblVzZSIgeDE9IjAlIiB5MT0iMCUiIHgyPSIxMDAlIiB5Mj0iMCUiPgogICAgPHN0b3Agb2Zmc2V0PSIwJSIgc3RvcC1jb2xvcj0iIzRmODFiZCIgc3RvcC1vcGFjaXR5PSIxIi8+CiAgICA8c3RvcCBvZmZzZXQ9IjEwMCUiIHN0b3AtY29sb3I9IiM4YWJiZDciIHN0b3Atb3BhY2l0eT0iMSIvPgogIDwvbGluZWFyR3JhZGllbnQ+CiAgPHJlY3QgeD0iMCIgeT0iMCIgd2lkdGg9IjEiIGhlaWdodD0iMSIgZmlsbD0idXJsKCNncmFkLXVjZ2ctZ2VuZXJhdGVkKSIgLz4KPC9zdmc+);
background: -moz-linear-gradient(left, #4f81bd 0%, #8abbd7 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, right top, color-stop(0%,#4f81bd), color-stop(100%,#8abbd7)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(left, #4f81bd 0%,#8abbd7 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(left, #4f81bd 0%,#8abbd7 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(left, #4f81bd 0%,#8abbd7 100%); /* IE10+ */
background: linear-gradient(left, #4f81bd 0%,#8abbd7 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#4f81bd', endColorstr='#8abbd7',GradientType=1 ); /* IE6-8 */

Was doing this to me and once I removed the "filter:" line the bleeding went away. Plus I use PIE.

Bleeds:

    background: #8abbd7; /* Old browsers */
/* IE9 SVG, needs conditional override of 'filter' to 'none' */
background: url(data:image/svg+xml;base64,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);
background: -moz-linear-gradient(top, #8abbd7 0%, #4f81bd 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#8abbd7), color-stop(100%,#4f81bd)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* IE10+ */
background: linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* W3C */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#8abbd7', endColorstr='#4f81bd',GradientType=0 ); /* IE6-8 */
-pie-background: linear-gradient(#8ABBD7, #4f81bd);
behavior: url(../PIE/PIE.htc);

Does not bleed:

    background: #8abbd7; /* Old browsers */
/* IE9 SVG, needs conditional override of 'filter' to 'none' */
background: url(data:image/svg+xml;base64,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);
background: -moz-linear-gradient(top, #8abbd7 0%, #4f81bd 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#8abbd7), color-stop(100%,#4f81bd)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* IE10+ */
background: linear-gradient(top, #8abbd7 0%,#4f81bd 100%); /* W3C */
-pie-background: linear-gradient(#8ABBD7, #4f81bd);
behavior: url(../PIE/PIE.htc);

Quick IE Shadow Fix:

fixBoxShadowBlur($('*'));

function fixBoxShadowBlur(jQueryObject){
if($.browser.msie && $.browser.version.substr(0, 1) == '9'){
    jQueryObject.each(function(){
        boxShadow = $(this).css('boxShadow');
        if(boxShadow != 'none'){
            var bsArr = boxShadow.split(' ');
            bsBlur = parseInt(bsArr[2]) || 0;
            bsBlurMeasureType = bsArr[2].substr(("" + bsBlur).length);
            bsArr[2] = (bsBlur * 2) + bsBlurMeasureType;
            $(this).css('boxShadow', bsArr.join(' '));
        }
    });
}

}

Discussion courtesy of: Shawn Rebelo

Using compass and sass you can easily achieve this like so:

@import "compass";
#border-radius {
@include border-radius('RADIUS'px); }
#gradiant{
$experimental-support-for-svg: true;
@include background-image(linear-gradient('COLOR') %,('COLOR') %,...; }

Compass will generate a SVG image for you.

like so:

#gradiant {
 background-image: url('data:image/svg+xml;base64,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');
background-size: 100%;
background-image: -webkit-gradient(linear, to bottom, to top, color-stop(0%, #082a2e),   color-stop(35%, rgba(8, 42, 46, 0.76)), color-stop(43%, rgba(7, 43, 47, 0.71)), color-stop(58%, rgba(4, 44, 50, 0.58)), color-stop(100%, #042c32));
background-image: -webkit-linear-gradient(to bottom, #082a2e 0%, rgba(8, 42, 46, 0.76) 35%, rgba(7, 43, 47, 0.71) 43%, rgba(4, 44, 50, 0.58) 58%, #042c32 100%);
background-image: -moz-linear-gradient(to bottom, #082a2e 0%, rgba(8, 42, 46, 0.76) 35%, rgba(7, 43, 47, 0.71) 43%, rgba(4, 44, 50, 0.58) 58%, #042c32 100%);
background-image: -o-linear-gradient(to bottom, #082a2e 0%, rgba(8, 42, 46, 0.76) 35%, rgba(7, 43, 47, 0.71) 43%, rgba(4, 44, 50, 0.58) 58%, #042c32 100%);
background-image: linear-gradient(to bottom, #082a2e 0%, rgba(8, 42, 46, 0.76) 35%, rgba(7, 43, 47, 0.71) 43%, rgba(4, 44, 50, 0.58) 58%, #042c32 100%);

}

/* line 28, ../sass/boxshadow.scss */
#border-radius {
 -moz-border-radius-topright: 8px;
  -webkit-border-top-right-radius: 8px;
   border-top-right-radius: 8px;
 -moz-border-radius-bottomright: 8px;
  -webkit-border-bottom-right-radius: 8px;
  border-bottom-right-radius: 8px;

}

Discussion courtesy of: raam86

Just use a wrapper div (rounded & overflow hidden) to clip the radius for IE9. Simple, works cross-browser. SVG, JS, and conditional comments are unnecessary.

<div class="ie9roundedgradient"><div class="roundedgradient">text or whatever</div></div>

.ie9roundedgradient { 
display:inline-block; overflow:hidden; -webkit-border-radius: 8px; -moz-border-radius: 8px; border-radius: 8px; 
}
.roundedgradient { 
-webkit-border-radius: 8px; -moz-border-radius: 8px; border-radius: 8px; 
/* use colorzilla to generate your cross-browser gradients */ 
}
Discussion courtesy of: Brian Lewis

I think it's worth mentioning that in many cases you can use an inset box-shadow to "fake" the gradient effect and avoid the ugly edges in IE9. This works especially well with buttons.

See this example: http://jsfiddle.net/jancbeck/CJPPW/31/

Comparison of a button style with either linear gradient or box-shadow

Discussion courtesy of: Jan Beck

I ran into this bug too. My suggestion would be to use a repeated background image for the gradient in ie9. IE9 correctly tiles the image behind the rounded borders (as of RC1).

I fail to see how writing 100 lines of code to replace 1 line of CSS is simple or elegant. SVG is cool and all, but why go through all that when easier solutions for gradient backgrounds have been around for years.

Discussion courtesy of: MikeP

This blog posting helped me: http://abouthalf.com/2010/10/25/internet-explorer-9-gradients-with-rounded-corners/

Basically, you use a conditional comment to remove the filter and then create SVG 'sprites' of gradients which you can use as background images.

Simple and elegant!

Discussion courtesy of: Dan Herd

There is a simple way to make it work under IE9 with just ONE element.

Take a look at this fiddle: http://jsfiddle.net/bhaBJ/6/

First element sets the Border-Radius. Second pseudo-Element sets the Background Gradient.

Few key instructions:

  • parent must have relative or absolute position
  • parent must have overflow: hidden; (in order to border-radius effect to be visible)
  • ::before (or ::after) pseudo-element must have z-index: -1 (workaround kind of)

Base element declaration goes something like:

.button{
    position: relative;
    overflow: hidden;        /*make childs not to overflow the parent*/

    border-radius: 5px;      /*don't forget to make it cross-browser*/

    z-index:2;               /*just to be sure*/
}

Pseudo-Element declaration:

.button:before{

    content: " ";                     /*make it a node*/
    display: block;     

    position: absolute;               
    top:0;left:0;bottom:0;right:0;    /*same width and height as parent*/

    z-index: -1;                      /*force it to NOT overlay the TEXT node*/

    /*GRADIENT declarations...*/
    background: -ms-linear-gradient(top,  #ff3232 0%,#7db9e8 100%);
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ff3232',endColorstr='#7db9e8',GradientType=0 );

}
Discussion courtesy of: Marakoss

Works for me...

<!--[if gte IE 9]>
  <style type="text/css">
  .gradient{
   filter: ;
}
</style>

css

border-radius: 10px;
background: #00a8db; /* Old browsers */
background: -moz-linear-gradient(top, #00a8db 0%, #116c8c 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#00a8db), color-    stop(100%,#116c8c)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, #00a8db 0%,#116c8c 100%); /* Chrome10+,Safari5.1+     */
background: -o-linear-gradient(top, #00a8db 0%,#116c8c 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, #00a8db 0%,#116c8c 100%); /* IE10+ */
background: linear-gradient(to bottom, #00a8db 0%,#116c8c 100%); /* W3C */
-webkit-box-shadow: 1px 5px 2px #999;
-moz-box-shadow: 1px 1px 5px #999;
box-shadow: 1px 1px 5px #999;
color: #fff;
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00a8db',     endColorstr='#116c8c',GradientType=0 ); /* IE6-8 */
/* IE9 SVG, needs conditional override of 'filter' to 'none' */
background:     url(data:image/svg+xml;base64,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);
/* W3C Markup, IE10 Release Preview */ 
background-image: linear-gradient(to top, #116C8C 0%, #00A5D7 100%);
Discussion courtesy of: user2132041

You could use shadow to achieve gradient, and is going to work on Internet Explorer 9 with border-radius

Something like this:

box-shadow: inset 0px 0px 26px 5px gainsboro;
Discussion courtesy of: Rajesh

You can also use CSS3 PIE to resolve this issue:

http://css3pie.com/

Of course, that might be overkill if you're just depending on a single element with rounded corners and a background gradient, but it is an option to consider if you're incorporating a number of common CSS3 features on your pages and want easy support for IE6+

Discussion courtesy of: Louis L.

Not sure if this was a one off or a valid workaround but...

I found that provided the border-radius is greater than the border width, I didn't encounter the issue. When they were the same I was getting the square corners.

Discussion courtesy of: daddywoodland

This recipe can be found in it's original form on Stack Over Flow.