CSS属性受到 transition effect的影响，会产生不断变化的中间值，而 CSS transition-timing-function 属性用来描述这个中间值是怎样计算的。实质上，通过这个函数会建立一条加速度曲线，因此在整个transition变化过程中，变化速度可以不断改变。

这条加速度曲线被{{cssxref("<timing-function>")}}所定义，之后作用到每个CSS属性的过渡.

你可以规定多个timing function,通过使用 {{ cssxref("transition-property") }}属性，可以根据主列表(transition property的列表)给每个CSS属性应用相应的timing function.如果timing function的个数比主列表中数量少，缺少的值被设置为初始值（ease）。如果timing function比主列表要多，timing function函数列表会被截断至合适的大小。这两种情况下声明的CSS属性都是有效的。

语法

值

示例

transition-timing-function: ease

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease;
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease;
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

transition-timing-function: ease-in

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
     -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease-in;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease-in;
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease-in;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease-in;
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

transition-timing-function: ease-out

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease-out;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease-out;
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease-out;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease-out;
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

transition-timing-function: ease-in-out

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease-in-out;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease-in-out;
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: ease-in-out;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: ease-in-out;
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

transition-timing-function: linear

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: linear;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: linear;
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: linear;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: linear;
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

transition-timing-function: step-start

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: step-start;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: step-start;
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: step-start;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: step-start;
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

transition-timing-function: step-end

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: step-end;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: step-end;
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: step-end;
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: step-end;
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

transition-timing-function: steps(4, end)

 <div class="parent">
  <div class="box">Lorem</div>
</div>

.parent { width: 250px; height:125px;}
.box {
    width: 100px;
    height: 100px;
    background-color: red;
    font-size: 20px;
    left: 0px;
    top: 0px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: steps(4, end);
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: steps(4, end);
}
.box1{
    width: 50px;
    height: 50px;
    background-color: blue;
    color: yellow;
    font-size: 18px;
    left: 150px;
    top:25px;
    position:absolute;
    -webkit-transition-property: width height background-color font-size left top color;
    -webkit-transition-duration:2s;
    -webkit-transition-timing-function: steps(4, end);
    transition-property: width height background-color font-size left top color;
    transition-duration:2s;
    transition-timing-function: steps(4, end);
}

function updateTransition() {
  var el = document.querySelector("div.box");

  if (el) {
    el.className = "box1";
  } else {
    el = document.querySelector("div.box1");
    el.className = "box";
  }

  return el;
}

var intervalID = window.setInterval(updateTransition, 7000);

概述

语法

值

示例

规范

浏览器兼容性

参考