渐变还不支持过渡(尽管目前的规范说它们应该通过插值支持类似渐变到类似渐变的过渡)。

如果你想要一个背景渐变的渐隐效果，你必须在容器元素上设置一个不透明度，然后“过渡”不透明度。

(已经有一些浏览器版本支持渐变过渡(例如IE10。我在2016年在IE中测试了梯度转换，当时它们似乎可以工作，但我的测试代码不再工作了。)

更新:2018年10月 带有无前缀新语法的渐变过渡[例如径向渐变(…)]现在确认在Microsoft Edge 17.17134上工作(再次?)我不知道这是什么时候加入的。在最新的Firefox和Chrome / Windows 10上仍然不能工作。

更新:2021年12月 在最近的基于Chromium的浏览器中，使用@property的变通方法可以实现这一点(但在Firefox中不起作用)。请在YMMV上方看到@mahozad的回答(并点赞)。

渐变还不支持过渡(尽管目前的规范说它们应该通过插值支持类似渐变到类似渐变的过渡)。

如果你想要一个背景渐变的渐隐效果，你必须在容器元素上设置一个不透明度，然后“过渡”不透明度。

(已经有一些浏览器版本支持渐变过渡(例如IE10。我在2016年在IE中测试了梯度转换，当时它们似乎可以工作，但我的测试代码不再工作了。)

更新:2018年10月 带有无前缀新语法的渐变过渡[例如径向渐变(…)]现在确认在Microsoft Edge 17.17134上工作(再次?)我不知道这是什么时候加入的。在最新的Firefox和Chrome / Windows 10上仍然不能工作。

更新:2021年12月 在最近的基于Chromium的浏览器中，使用@property的变通方法可以实现这一点(但在Firefox中不起作用)。请在YMMV上方看到@mahozad的回答(并点赞)。

一种解决方法是转换背景位置，以产生渐变变化的效果: http://sapphion.com/2011/10/css3-gradient-transition-with-background-position/

CSS3渐变过渡与背景位置 虽然你不能直接使用CSS的transition属性来动画渐变，但是你可以使用background-position属性来实现简单的渐变动画: 它的代码非常简单:

#DemoGradient{ background: -webkit-linear-gradient(#C7D3DC,#5B798E); background: -moz-linear-gradient(#C7D3DC,#5B798E); background: -o-linear-gradient(#C7D3DC,#5B798E); background: linear-gradient(#C7D3DC,#5B798E); -webkit-transition: background 1s ease-out; -moz-transition: background 1s ease-out; -o-transition: background 1s ease-out; transition: background 1s ease-out; background-size:1px 200px; border-radius: 10px; border: 1px solid #839DB0; cursor:pointer; width: 150px; height: 100px; } #DemoGradient:Hover{ background-position:100px; } <div id="DemoGradient"></div>

我知道这是一个老问题，但也许有人喜欢我在纯CSS解决方案的方式。从左到右渐变。

.contener{ width:300px; height:200px; background-size:cover; border:solid 2px black; } .ed { width: 0px; height: 200px; background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.75)); position: relative; opacity:0; transition:width 20s, opacity 0.6s; } .contener:hover .ed{ width: 300px; background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.75)); position: relative; opacity:1; transition:width 0.4s, opacity 1.1s; transition-delay: width 2s; animation-name: gradient-fade; animation-duration: 1.1s; -webkit-animation-name: gradient-fade; /* Chrome, Safari, Opera */ -webkit-animation-duration: 1.1s; /* Chrome, Safari, Opera */ } /* ANIMATION */ @-webkit-keyframes gradient-fade { 0% {background:linear-gradient(to right, rgba(0,0,255,0), rgba(255,0,0,0));} 2% {background:linear-gradient(to right, rgba(0,0,255,0.01875), rgba(255,0,0,0));} 4% {background:linear-gradient(to right, rgba(0,0,255,0.0375), rgba(255,0,0,0.0));} 6% {background:linear-gradient(to right, rgba(0,0,255,0.05625), rgba(255,0,0,0.0));} 8% {background:linear-gradient(to right, rgba(0,0,255,0.075), rgba(255,0,0,0));} 10% {background:linear-gradient(to right, rgba(0,0,255,0.09375), rgba(255,0,0,0));} 12% {background:linear-gradient(to right, rgba(0,0,255,0.1125), rgba(255,0,0,0));} 14% {background:linear-gradient(to right, rgba(0,0,255,0.13125), rgba(255,0,0,0));} 16% {background:linear-gradient(to right, rgba(0,0,255,0.15), rgba(255,0,0,0));} 18% {background:linear-gradient(to right, rgba(0,0,255,0.16875), rgba(255,0,0,0));} 20% {background:linear-gradient(to right, rgba(0,0,255,0.1875), rgba(255,0,0,0));} 22% {background:linear-gradient(to right, rgba(0,0,255,0.20625), rgba(255,0,0,0.01875));} 24% {background:linear-gradient(to right, rgba(0,0,255,0.225), rgba(255,0,0,0.0375));} 26% {background:linear-gradient(to right, rgba(0,0,255,0.24375), rgba(255,0,0,0.05625));} 28% {background:linear-gradient(to right, rgba(0,0,255,0.2625), rgba(255,0,0,0.075));} 30% {background:linear-gradient(to right, rgba(0,0,255,0.28125), rgba(255,0,0,0.09375));} 32% {background:linear-gradient(to right, rgba(0,0,255,0.3), rgba(255,0,0,0.1125));} 34% {background:linear-gradient(to right, rgba(0,0,255,0.31875), rgba(255,0,0,0.13125));} 36% {background:linear-gradient(to right, rgba(0,0,255,0.3375), rgba(255,0,0,0.15));} 38% {background:linear-gradient(to right, rgba(0,0,255,0.35625), rgba(255,0,0,0.16875));} 40% {background:linear-gradient(to right, rgba(0,0,255,0.375), rgba(255,0,0,0.1875));} 42% {background:linear-gradient(to right, rgba(0,0,255,0.39375), rgba(255,0,0,0.20625));} 44% {background:linear-gradient(to right, rgba(0,0,255,0.4125), rgba(255,0,0,0.225));} 46% {background:linear-gradient(to right, rgba(0,0,255,0.43125),rgba(255,0,0,0.24375));} 48% {background:linear-gradient(to right, rgba(0,0,255,0.45), rgba(255,0,0,0.2625));} 50% {background:linear-gradient(to right, rgba(0,0,255,0.46875), rgba(255,0,0,0.28125));} 52% {background:linear-gradient(to right, rgba(0,0,255,0.4875), rgba(255,0,0,0.3));} 54% {background:linear-gradient(to right, rgba(0,0,255,0.50625), rgba(255,0,0,0.31875));} 56% {background:linear-gradient(to right, rgba(0,0,255,0.525), rgba(255,0,0,0.3375));} 58% {background:linear-gradient(to right, rgba(0,0,255,0.54375), rgba(255,0,0,0.35625));} 60% {background:linear-gradient(to right, rgba(0,0,255,0.5625), rgba(255,0,0,0.375));} 62% {background:linear-gradient(to right, rgba(0,0,255,0.58125), rgba(255,0,0,0.39375));} 64% {background:linear-gradient(to right,rgba(0,0,255,0.6), rgba(255,0,0,0.4125));} 66% {background:linear-gradient(to right, rgba(0,0,255,0.61875), rgba(255,0,0,0.43125));} 68% {background:linear-gradient(to right, rgba(0,0,255,0.6375), rgba(255,0,0,0.45));} 70% {background:linear-gradient(to right, rgba(0,0,255,0.65625), rgba(255,0,0,0.46875));} 72% {background:linear-gradient(to right, rgba(0,0,255,0.675), rgba(255,0,0,0.4875));} 74% {background:linear-gradient(to right, rgba(0,0,255,0.69375), rgba(255,0,0,0.50625));} 76% {background:linear-gradient(to right, rgba(0,0,255,0.7125), rgba(255,0,0,0.525));} 78% {background:linear-gradient(to right, rgba(0,0,255,0.73125),,rgba(255,0,0,0.54375));} 80% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.5625));} 82% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.58125));} 84% {background:linear-gradient(to right, rgba(0,0,255,0.75),rgba(255,0,0,0.6));} 86% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.61875));} 88% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.6375));} 90% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.65625));} 92% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.675));} 94% {background:linear-gradient(to right, rgba(0,0,255,0.75),rgba(255,0,0,0.69375));} 96% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.7125));} 98% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.73125),);} 100% {background:linear-gradient(to right, rgba(0,0,255,0.75), rgba(255,0,0,0.75));} } <div class="contener" style=""> <div class="ed"></div> </div>

一个更简洁的解决方案是设置背景色并使用蒙版图像。

#container div a {
  background-color: blue;
  transition: background 0.2s linear;
  width: 200px;
  height: 150px;
  mask-image: radial-gradient(circle at 50% 50%, rgba(0, 0, 0, .7), rgba(0, 0, 0, .4));
}

#container div a:hover { 
  background-color: red;
}

你可以伪造渐变之间的过渡，在一些堆叠渐变的不透明度中使用过渡，正如这里的一些答案所描述的:

CSS3动画与梯度。

你也可以转换位置，如下所述:

CSS3渐变过渡与背景位置。

这里还有一些技巧:

动画CSS3渐变。