在较新的浏览器中，如Chrome 15, Firefox 10, Safari 5.1, IE 10，这是可能的。根据浏览器设置，旧版本的IE也可以通过ActiveX实现。

以下是如何做到这一点:

function requestFullScreen(element) {
    // Supports most browsers and their versions.
    var requestMethod = element.requestFullScreen || element.webkitRequestFullScreen || element.mozRequestFullScreen || element.msRequestFullScreen;

    if (requestMethod) { // Native full screen.
        requestMethod.call(element);
    } else if (typeof window.ActiveXObject !== "undefined") { // Older IE.
        var wscript = new ActiveXObject("WScript.Shell");
        if (wscript !== null) {
            wscript.SendKeys("{F11}");
        }
    }
}

var elem = document.body; // Make the body go full screen.
requestFullScreen(elem);

用户显然需要首先接受全屏请求，并且不可能在页面加载时自动触发此请求，它需要由用户触发(例如。一个按钮)

阅读更多信息:https://developer.mozilla.org/en/DOM/Using_full-screen_mode

这个函数非常好用

function toggle_full_screen()
{
    if ((document.fullScreenElement && document.fullScreenElement !== null) || (!document.mozFullScreen && !document.webkitIsFullScreen))
    {
        if (document.documentElement.requestFullScreen){
            document.documentElement.requestFullScreen();
        }
        else if (document.documentElement.mozRequestFullScreen){ /* Firefox */
            document.documentElement.mozRequestFullScreen();
        }
        else if (document.documentElement.webkitRequestFullScreen){   /* Chrome, Safari & Opera */
            document.documentElement.webkitRequestFullScreen(Element.ALLOW_KEYBOARD_INPUT);
        }
        else if (document.msRequestFullscreen){ /* IE/Edge */
            document.documentElement.msRequestFullscreen();
        }
    }
    else
    {
        if (document.cancelFullScreen){
            document.cancelFullScreen();
        }
        else if (document.mozCancelFullScreen){ /* Firefox */
            document.mozCancelFullScreen();
        }
        else if (document.webkitCancelFullScreen){   /* Chrome, Safari and Opera */
            document.webkitCancelFullScreen();
        }
        else if (document.msExitFullscreen){ /* IE/Edge */
            document.msExitFullscreen();
        }
    }
}

要使用它，只需调用:

toggle_full_screen();

这里有一个完整的解决方案，以进入和退出全屏模式(即取消，退出，退出)

        function cancelFullScreen() {
            var el = document;
            var requestMethod = el.cancelFullScreen||el.webkitCancelFullScreen||el.mozCancelFullScreen||el.exitFullscreen||el.webkitExitFullscreen;
            if (requestMethod) { // cancel full screen.
                requestMethod.call(el);
            } else if (typeof window.ActiveXObject !== "undefined") { // Older IE.
                var wscript = new ActiveXObject("WScript.Shell");
                if (wscript !== null) {
                    wscript.SendKeys("{F11}");
                }
            }
        }

        function requestFullScreen(el) {
            // Supports most browsers and their versions.
            var requestMethod = el.requestFullScreen || el.webkitRequestFullScreen || el.mozRequestFullScreen || el.msRequestFullscreen;

            if (requestMethod) { // Native full screen.
                requestMethod.call(el);
            } else if (typeof window.ActiveXObject !== "undefined") { // Older IE.
                var wscript = new ActiveXObject("WScript.Shell");
                if (wscript !== null) {
                    wscript.SendKeys("{F11}");
                }
            }
            return false
        }

        function toggleFullScreen(el) {
            if (!el) {
                el = document.body; // Make the body go full screen.
            }
            var isInFullScreen = (document.fullScreenElement && document.fullScreenElement !== null) ||  (document.mozFullScreen || document.webkitIsFullScreen);

            if (isInFullScreen) {
                cancelFullScreen();
            } else {
                requestFullScreen(el);
            }
            return false;
        }

在较新的浏览器中，如Chrome 15, Firefox 10, Safari 5.1, IE 10，这是可能的。根据浏览器设置，旧版本的IE也可以通过ActiveX实现。

以下是如何做到这一点:

function requestFullScreen(element) {
    // Supports most browsers and their versions.
    var requestMethod = element.requestFullScreen || element.webkitRequestFullScreen || element.mozRequestFullScreen || element.msRequestFullScreen;

    if (requestMethod) { // Native full screen.
        requestMethod.call(element);
    } else if (typeof window.ActiveXObject !== "undefined") { // Older IE.
        var wscript = new ActiveXObject("WScript.Shell");
        if (wscript !== null) {
            wscript.SendKeys("{F11}");
        }
    }
}

var elem = document.body; // Make the body go full screen.
requestFullScreen(elem);

用户显然需要首先接受全屏请求，并且不可能在页面加载时自动触发此请求，它需要由用户触发(例如。一个按钮)

阅读更多信息:https://developer.mozilla.org/en/DOM/Using_full-screen_mode

这是JavaScript中最接近全屏的效果:

<script type="text/javascript">
    window.onload = maxWindow;

    function maxWindow() {
        window.moveTo(0, 0);

        if (document.all) {
            top.window.resizeTo(screen.availWidth, screen.availHeight);
        }

        else if (document.layers || document.getElementById) {
            if (top.window.outerHeight < screen.availHeight || top.window.outerWidth < screen.availWidth) {
                top.window.outerHeight = screen.availHeight;
                top.window.outerWidth = screen.availWidth;
            }
        }
    }
</script> 

这将在全屏显示你的窗口

注意:要使其工作，您需要来自http://code.jquery.com/jquery-2.1.1.min.js的Query

或者让javascript链接像这样。

<script src="http://code.jquery.com/jquery-2.1.1.min.js"></script>

   <div id="demo-element">
        <span>Full Screen Mode Disabled</span>
        <button id="go-button">Enable Full Screen</button>
    </div>
    <script>
    function GoInFullscreen(element) {
        if(element.requestFullscreen)
            element.requestFullscreen();
        else if(element.mozRequestFullScreen)
            element.mozRequestFullScreen();
        else if(element.webkitRequestFullscreen)
            element.webkitRequestFullscreen();
        else if(element.msRequestFullscreen)
            element.msRequestFullscreen();
    }

    function GoOutFullscreen() {
        if(document.exitFullscreen)
            document.exitFullscreen();
        else if(document.mozCancelFullScreen)
            document.mozCancelFullScreen();
        else if(document.webkitExitFullscreen)
            document.webkitExitFullscreen();
        else if(document.msExitFullscreen)
            document.msExitFullscreen();
    }

    function IsFullScreenCurrently() {
        var full_screen_element = document.fullscreenElement || document.webkitFullscreenElement || document.mozFullScreenElement || document.msFullscreenElement || null;

        if(full_screen_element === null)
            return false;
        else
            return true;
    }

    $("#go-button").on('click', function() {
        if(IsFullScreenCurrently())
            GoOutFullscreen();
        else
            GoInFullscreen($("#demo-element").get(0));
    });

    $(document).on('fullscreenchange webkitfullscreenchange mozfullscreenchange MSFullscreenChange', function() {
        if(IsFullScreenCurrently()) {
            $("#demo-element span").text('Full Screen Mode Enabled');
            $("#go-button").text('Disable Full Screen');
        }
        else {
            $("#demo-element span").text('Full Screen Mode Disabled');
            $("#go-button").text('Enable Full Screen');
        }
    });</script>