根据MDN关于使用用户代理进行浏览器检测的文章，建议尽可能避免这种方法，并建议使用其他方法，如特征检测。

然而，如果必须使用用户代理作为检测设备是否移动的手段，他们建议:

总而言之，我们建议在中的任何地方查找字符串“Mobi” 用户代理检测移动设备。

因此，这一行代码就足够了:

const isMobileDevice = window.navigator.userAgent.toLowerCase().includes("mobi");

(更新):

正如@ zenwolf在评论中建议的那样，使用正则表达式会更好:

const isMobileDevice = /Mobi/i.test(window.navigator.userAgent)

啊，是的，这个古老的问题……

这取决于你对知识的反应。

1. 你想改变UI，让它适合不同的屏幕尺寸吗?

使用媒体查询。

2. 你想显示/隐藏东西或改变基于鼠标和触摸的功能吗?

上面的答案可以解决问题，但也可能出现用户同时拥有两个选项并切换的情况。在这种情况下，当你检测到鼠标或触摸事件时，你可以切换一些JS变量和/或向文档主体添加一个类

  window.addEventListener("mousemove", function () {
    isTouch = false;
    document.body.classList.add("canHover");
  });
  window.addEventListener("touchstart", function () {
    isTouch = true;
    document.body.classList.remove("canHover");
  });

body.canHover #aButtonOrSomething:hover {
  //css attributes
}

  document
    .getElementById("aButtonOrSomething")
    .addEventListener("mouseover", showTooltip);
  document
    .getElementById("aButtonOrSomething")
    .addEventListener("click", function () {
      if (isTouch) showTooltip();
    });

3.你想做一些具体的事情，知道他们有什么设备吗?

使用公认的答案。

这是他的全部功能

function isMobile(){
    return (/(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows (ce|phone)|xda|xiino|android|ipad|playbook|silk/i.test(navigator.userAgent||navigator.vendor||window.opera)||/1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test((navigator.userAgent||navigator.vendor||window.opera).substr(0,4)))
}

jQuery.noConflict();
jQuery(document).ready(function(){
    if(isMobile()) alert("Mobile"); else alert("Not Mobile");
});

我还没看到有人建议:

window.navigator.connection.type

这只存在于移动设备上，不存在于桌面浏览器上。检查该属性是否存在更简单，即if(window && window。Navigator && window.navigator.connection && window.navigator.connection.type) =>那么它是移动的

注意:这是实验性的

EDIT(07.2022):该功能被认为是一个潜在的跟踪漏洞，因此将从最新版本中删除。换句话说，不要用这个!

我建议你去http://wurfl.io/看看

简而言之，如果你导入一个很小的JS文件:

<script type='text/javascript' src="//wurfl.io/wurfl.js"></script>

你将得到一个JSON对象，看起来像:

{
 "complete_device_name":"Google Nexus 7",
 "is_mobile":true,
 "form_factor":"Tablet"
}

(当然，这是假设你使用的是Nexus 7)，你将能够做以下事情:

if(WURFL.form_factor == "Tablet"){
    //dostuff();
}

这就是你要找的。

免责声明:我为提供这项免费服务的公司工作。谢谢。

请注意，现在大多数新一代移动设备的分辨率都大于600x400。例如，一部iPhone 6....

测试证明: 在这里运行最多赞和最近的帖子，有一个可选的检查，像这样运行:

(function(a){
    window.isMobile = (/(android|bb\d+|meego).+mobile|avantgo|bada\/|blackberry|blazer|compal|elaine|fennec|hiptop|iemobile|ip(hone|od)|iris|kindle|lge |maemo|midp|mmp|mobile.+firefox|netfront|opera m(ob|in)i|palm( os)?|phone|p(ixi|re)\/|plucker|pocket|psp|series(4|6)0|symbian|treo|up\.(browser|link)|vodafone|wap|windows ce|xda|xiino/i.test(a)||/1207|6310|6590|3gso|4thp|50[1-6]i|770s|802s|a wa|abac|ac(er|oo|s\-)|ai(ko|rn)|al(av|ca|co)|amoi|an(ex|ny|yw)|aptu|ar(ch|go)|as(te|us)|attw|au(di|\-m|r |s )|avan|be(ck|ll|nq)|bi(lb|rd)|bl(ac|az)|br(e|v)w|bumb|bw\-(n|u)|c55\/|capi|ccwa|cdm\-|cell|chtm|cldc|cmd\-|co(mp|nd)|craw|da(it|ll|ng)|dbte|dc\-s|devi|dica|dmob|do(c|p)o|ds(12|\-d)|el(49|ai)|em(l2|ul)|er(ic|k0)|esl8|ez([4-7]0|os|wa|ze)|fetc|fly(\-|_)|g1 u|g560|gene|gf\-5|g\-mo|go(\.w|od)|gr(ad|un)|haie|hcit|hd\-(m|p|t)|hei\-|hi(pt|ta)|hp( i|ip)|hs\-c|ht(c(\-| |_|a|g|p|s|t)|tp)|hu(aw|tc)|i\-(20|go|ma)|i230|iac( |\-|\/)|ibro|idea|ig01|ikom|im1k|inno|ipaq|iris|ja(t|v)a|jbro|jemu|jigs|kddi|keji|kgt( |\/)|klon|kpt |kwc\-|kyo(c|k)|le(no|xi)|lg( g|\/(k|l|u)|50|54|\-[a-w])|libw|lynx|m1\-w|m3ga|m50\/|ma(te|ui|xo)|mc(01|21|ca)|m\-cr|me(rc|ri)|mi(o8|oa|ts)|mmef|mo(01|02|bi|de|do|t(\-| |o|v)|zz)|mt(50|p1|v )|mwbp|mywa|n10[0-2]|n20[2-3]|n30(0|2)|n50(0|2|5)|n7(0(0|1)|10)|ne((c|m)\-|on|tf|wf|wg|wt)|nok(6|i)|nzph|o2im|op(ti|wv)|oran|owg1|p800|pan(a|d|t)|pdxg|pg(13|\-([1-8]|c))|phil|pire|pl(ay|uc)|pn\-2|po(ck|rt|se)|prox|psio|pt\-g|qa\-a|qc(07|12|21|32|60|\-[2-7]|i\-)|qtek|r380|r600|raks|rim9|ro(ve|zo)|s55\/|sa(ge|ma|mm|ms|ny|va)|sc(01|h\-|oo|p\-)|sdk\/|se(c(\-|0|1)|47|mc|nd|ri)|sgh\-|shar|sie(\-|m)|sk\-0|sl(45|id)|sm(al|ar|b3|it|t5)|so(ft|ny)|sp(01|h\-|v\-|v )|sy(01|mb)|t2(18|50)|t6(00|10|18)|ta(gt|lk)|tcl\-|tdg\-|tel(i|m)|tim\-|t\-mo|to(pl|sh)|ts(70|m\-|m3|m5)|tx\-9|up(\.b|g1|si)|utst|v400|v750|veri|vi(rg|te)|vk(40|5[0-3]|\-v)|vm40|voda|vulc|vx(52|53|60|61|70|80|81|83|85|98)|w3c(\-| )|webc|whit|wi(g |nc|nw)|wmlb|wonu|x700|yas\-|your|zeto|zte\-/i.test(a.substr(0,4)))
})(navigator.userAgent||navigator.vendor||window.opera);

alert("This browser was found to be a % browser.", window.isMobile ? 'mobile' : 'desktop');

不知何故，在以下浏览器应用程序上返回了以下结果。配置:iPhone 6S, iOS 10.3.1。

Safari(最新):将其作为移动设备检测。

Chrome(最新):没有检测到它作为一个移动。

SO, i then tested the suggestion from Lanti (https://stackoverflow.com/a/31864119/7183483), and it did return the proper results (mobile for all iOS devices, and desktop for my Mac). Therefore, i proceeded to edit it a little since it would fire twice (for both mobile and Tablet). I then noticed when testing on an iPad, that it also returned as a mobile, which makes sense, since the Parameters that Lanti uses check the OS more than anything. Therefore, i simply moved the tablet IF statement inside the mobile check, which would return mobile is the Tablet check was negative, and tablet otherwise. I then added the else clause for the mobile check to return as desktop/laptop, since both qualify, but then noticed that the browser detects CPU and OS brand. So i added what is returned in there as part of else if statement instead. To cap it, I added a cautionary else statement in case nothing was detected. See bellow, will update with a test on a Windows 10 PC soon.

哦，我还添加了一个'debugMode'变量，以便在调试和正常编译之间轻松切换。

Dislaimer:这完全是Lanti的功劳，而且这款游戏没有在Windows平板电脑上测试……它可能会返回桌面/笔记本电脑，因为操作系统是纯Windows。等我找到用手机的朋友我会查的。

function userAgentDetect() {
    let debugMode = true;
    if(window.navigator.userAgent.match(/Mobile/i)
        || window.navigator.userAgent.match(/iPhone/i)
        || window.navigator.userAgent.match(/iPod/i)
        || window.navigator.userAgent.match(/IEMobile/i)
        || window.navigator.userAgent.match(/Windows Phone/i)
        || window.navigator.userAgent.match(/Android/i)
        || window.navigator.userAgent.match(/BlackBerry/i)
        || window.navigator.userAgent.match(/webOS/i)) {
        if (window.navigator.userAgent.match(/Tablet/i)
            || window.navigator.userAgent.match(/iPad/i)
            || window.navigator.userAgent.match(/Nexus 7/i)
            || window.navigator.userAgent.match(/Nexus 10/i)
            || window.navigator.userAgent.match(/KFAPWI/i)) {
            window.deviceTypeVar = 'tablet';
            if (debugMode === true) {
                alert('Device is a tablet - ' + navigator.userAgent);
            }
        } else {
            if (debugMode === true) {
                alert('Device is a smartphone - ' + navigator.userAgent);
            };
            window.deviceTypeVar = 'smartphone';
        }
    } else if (window.navigator.userAgent.match(/Intel Mac/i)) {
        if (debugMode === true) {
            alert('Device is a desktop or laptop- ' + navigator.userAgent);
        }
        window.deviceTypeVar = 'desktop_or_laptop';
    } else if (window.navigator.userAgent.match(/Nexus 7/i)
        || window.navigator.userAgent.match(/Nexus 10/i)
        || window.navigator.userAgent.match(/KFAPWI/i)) {
        window.deviceTypeVar = 'tablet';
        if (debugMode === true) {
            alert('Device is a tablet - ' + navigator.userAgent);
        }
    } else {
        if (debugMode === true) {
            alert('Device is unknown- ' + navigator.userAgent);
        }
        window.deviceTypeVar = 'Unknown';
    }
}