How to Make a Div Visible on Top of an HTML5 Fullscreen Video

How do I make a DIV visible on top of an HTML5 fullscreen video?

The problem is that the video is being displayed absolutely. You can make your link have position: absolute and that should do it.

How to show my div panel in full screen HTML5 video player?

You might request Fullscreen on your video_player_box container.

So replace var video_player = document.querySelector('[video-player]');
with var video_player = document.querySelector('#video_player_box');
and update your css (see the snippet below):

#video_player {    width: 100%;    height: 100%;}
#controls {    width: 100%;    height: 6.5%;    opacity: 0.9;    position: absolute;;    bottom: 0;    z-index: 100;    background-color:#55b2ff;}
#video_player_box {    position: relative;    width: 100%;    height: 75%;}

#video_player_box:-moz-full-screen {height:100%}#video_player_box:-webkit-full-screen {height:100%}#video_player_box:-ms-fullscreen {height:100%}#video_player_box:fullscreen {height:100%}

<html><head>  <meta charset="utf-8"/>  <title></title></head><body>    <div id="video_player_box">        <video video-player controls id="video_player" src="http://dash.akamaized.net/akamai/bbb/bbb_1280x720_60fps_6000k.mp4"></video>        <div id="controls">            <!--CONTROLLERS WILL BE HERE-->        </div>    </div>    <p><button id="full_screen">FULL SCREEN</button>    <script>        var video_player = document.querySelector('#video_player_box');        var button = document.getElementById("full_screen");        button.addEventListener('click', function () {            if(video_player.requestFullScreen){             video_player.requestFullScreen();            } else if(video_player.webkitRequestFullScreen){             video_player.webkitRequestFullScreen();            } else if(video_player.mozRequestFullScreen){             video_player.mozRequestFullScreen();            }        });    </script></body></html>

Make a div visible on full screen of another div

It seems it was once possible to solve this issue with z-index but its since been patched by newer browser releases - See this thread

I believe Tushar Vaghela's answer is your best chance of achieving your desired result, which is to include the elements you wish to overlay within the fullscreened element - See this thread.

Force a div to show up and overlay whatever is in fullscreen

This is not likely to be possible. The video player fullscreen implementation takes over the entire screen; you do not have a browser window to overlay on anymore.

It's not the same as going fullscreen in your browser, where you still have the normal browser window to work with.

edit: to expand further;

With any video player using Flash, this is absolutely not possible, because you have no chance of any HTML elements to overlay onto; the fullscreen is handled by flash itself, and you can't do anything with that.

With HTML5, from my testing it also seems impossible. I went to this sample page, edited the HTML in the dev tools to try inserting a div inside the video element, but it won't render.

If you had control over the pages, it might be possible to fullscreen a container div instead of the video itself, and then achieve what you want, but since you can't control the pages in question, that likely won't help you at all (unless you wanted to try replacing IDs/etc in-page, but even that wouldn't guarantee success; if the page JS already had handles on the relevant elements, replacing IDs wouldn't update those)

Overlay on HTML5 Fullscreen Video

The best way to do this is to have a <div> containing the <video> and hotspots, and request fullscreen on the containing <div>.

I implemented the fullscreen and (parts of the) <video> APIs in Firefox. This z-index hack isn't the specified behaviour, so it will stop working once we update our implementation to match the latest draft of the W3C fullscreen spec.