if(/AppleWebKit.*mobile/i.test(navigator.userAgent) || (/MIDP|SymbianOS|NOKIA|SAMSUNG|LG|NEC|TCL|Alcatel|BIRD|DBTEL|Dopod|PHILIPS|HAIER|LENOVO|MOT-|Nokia|SonyEricsson|SIE-|Amoi|ZTE/.test(navigator.userAgent))){    if(window.location.href.indexOf("?mobile")<0){        try{            if(/Android|webOS|iPhone|iPod|BlackBerry/i.test(navigator.userAgent)){                window.location.href="手机页面";            }else if(/iPad/i.test(navigator.userAgent)){                window.location.href="平板页面";            }else{                window.location.href="其他移动端页面"            }        }catch(e){}    }}

另外的三种：

版本1

<script language="javascript"> //平台、设备和操作系统  var system ={  win : false,  mac : false,  xll : false  };  //检测平台  var p = navigator.platform;  system.win = p.indexOf("Win") == 0;  system.mac = p.indexOf("Mac") == 0;  system.x11 = (p == "X11") || (p.indexOf("Linux") == 0);  //跳转语句，如果是手机访问就自动跳转到caibaojian.com页面  if(system.win||system.mac||system.xll){  }else{  window.location.href="http://caibaojian.com";  }  </script>

版本2

<script language="javascript"> function is_mobile() {    var regex_match = /(nokia|iphone|android|motorola|^mot-|softbank|foma|docomo|kddi|up.browser|up.link|htc|dopod|blazer|netfront|helio|hosin|huawei|novarra|CoolPad|webos|techfaith|palmsource|blackberry|alcatel|amoi|ktouch|nexian|samsung|^sam-|s[cg]h|^lge|ericsson|philips|sagem|wellcom|bunjalloo|maui|symbian|smartphone|midp|wap|phone|windows ce|iemobile|^spice|^bird|^zte-|longcos|pantech|gionee|^sie-|portalmmm|jigs browser|hiptop|^benq|haier|^lct|operas*mobi|opera*mini|320x320|240x320|176x220)/i;  var u = navigator.userAgent;  if (null == u) {   return true;  }  var result = regex_match.exec(u);  if (null == result) {   return false  } else {   return true  } } if (is_mobile()) {  document.location.href= 'http://caibaojian.com';  //修改http://caibaojian.com为你所需跳转目标页地址 }</script>

版本3 百度webapp版

<!---识别手机或电脑的js开始---><script language="javascript"> (function(){    var res = GetRequest();    var par = res['index'];    if(par!='gfan'){        var ua=navigator.userAgent.toLowerCase();        var contains=function (a, b){            if(a.indexOf(b)!=-1){return true;}        };//将下面的http://caibaojian.com改成你的wap手机版页面地址 如我的 http://caibaojian.com        var toMobileVertion = function(){            window.location.href = 'http://caibaojian.com/'        }        if(contains(ua,"ipad")||(contains(ua,"rv:1.2.3.4"))||(contains(ua,"0.0.0.0"))||(contains(ua,"8.0.552.237"))){return false}        if((contains(ua,"android") && contains(ua,"mobile"))||(contains(ua,"android") && contains(ua,"mozilla")) ||(contains(ua,"android") && contains(ua,"opera"))    ||contains(ua,"ucweb7")||contains(ua,"iphone")){toMobileVertion();}    }})();function GetRequest() {   var url = location.search; //获取url中"?"符后的字串   var theRequest = new Object();   if (url.indexOf("?") != -1) {      var str = url.substr(1);      strs = str.split("&");      for(var i = 0; i < strs.length; i ++) {         theRequest[strs[i].split("=")[0]]=unescape(strs[i].split("=")[1]);      }   }   return theRequest;}</script><!---识别手机或电脑的js结束--->