Very simple method to add custom poster frame to youtube video without using youtube API. This code is also valid in browsers not supporting window.postMessage (API uses postMessage). The trick is adding the iframe in a comment. Javascript reads comment contents and saves iframe definition to a var. When JQuery (for the sake of brevity, not real…

youtube-poster-frame.css

.video { position: relative; padding-bottom: 56.25%; /* 16:9 */ height: 0; }
.video img { position: absolute; display: block; top: 0; left: 0; width: 100%; height: 100%; z-index: 20; cursor: pointer; }
.video:after { content: ""; position: absolute; display: block; 
    background: url(play-button.png) no-repeat 0 0; 
    top: 45%; left: 45%; width: 46px; height: 36px; z-index: 30; cursor: pointer; } 
.video iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

/* image poster clicked, player class added using js */
.video.player img { display: none; }
.video.player:after { display: none; }

youtube-poster-frame.html

<div class="video">
    <img src="poster.jpg">
    <!-- <iframe width="940" height="529" src="http://www.youtube.com/embed/rRoy6I4gKWU?autoplay=1" frameborder="0" allowfullscreen></iframe>-->
</div>

youtube-poster-frame.js

$(function() { 
    var videos  = $(".video");

        videos.on("click", function(){
            var elm = $(this),
                conts   = elm.contents(),
                le      = conts.length,
                ifr     = null;

            for(var i = 0; i<le; i++){
              if(conts[i].nodeType == 8) ifr = conts[i].textContent;
            }

            elm.addClass("player").html(ifr);
            elm.off("click");
        });
});

This is a handy script, thankyou. I had one issue in IE8 however – nodeTypes are not constants in IE8 as explained here with workaround: http://webbugtrack.blogspot.co.uk/2007/10/bug-256-dom-nodetype-constants-are-not.html

The problem I had in IE8 was conts[i].textContent returned as undefined. There were a couple of alternatives in IE8, but I went with conts[i].nodeValue. This may help someone else dealing with the same issue.

Instead of an html comment you can put the details of the iframe into a data attribute. You'd have to change the JS but it would be simpler,m more reliable jquery instead of counting nodes and inspecting nodeTypes

Is this working for you guys? The youtube-poster-frame.css seems to make things worse. Most swipes result in the video starting as well. Here's my jsFiddle demonstrating this. Any help would be appreciated!

I have made some adjustments to it. I want video to be image again when i change slide. Also, giving data atribute instead of comment seems much better to me.

$(function () {
        var videos = $(".YTvideo");

        $('#YTslider').on('afterChange', function () {
            videos.children('iframe').remove();
            videos.removeClass('player');
        });


        videos.on("click", function () {
            var that = $(this);

            setTimeout(function () {
                var YTid = that.data('yt_id');
                that.addClass("player").append('<iframe width="940" height="529" src="http://www.youtube.com/embed/' + YTid + '?autoplay=1" frameborder="0" allowfullscreen></iframe>');
            }, 400);
        });

    });

PS: you can get jpg from youtube video from this url: http://img.youtube.com/vi/0VF8GhZhFos/maxresdefault.jpg

hi there I'm new and this would help me a lot with my current project! can you please post the html too?
Because I don't know how to get the YTid and where do you use the #YTslider.

I´ve not tested it, but i think that ?autoplay=1 won´t work on IOS & Android, so users will have to make a second click... Any solution to this?

I've tried it, but the only thing that works is setting the iframe, but without the id, so it doesn't work. And it woun't remove the iframe with a second click, it just sets another iframe..

Really good job on the site, Keep up the good work!
Baa baa Black Sheep

can you explain what this for statement does?

for (var i = 0; i < length; i++) { if (conts[i].nodeType == 8) ifr = conts[i].textContent; }

@thecopelandcollective

That code is iterating through the contents of the element, and if it's an HTML comment (https://developer.mozilla.org/en-US/docs/Web/API/Node/nodeType .... see constant value of 8) then essentially uncomment it, which in turn loads the iframe.

its not working the iframe not loads

hi sorry to disturb you guys, but where do I put the script? just before the div from the video ?

Works perfectly, and makes pages with a bunch of videos load fast. Thanks!

I tried this technic for add a poster to a youtube video. It didn't worked at beginning, but I suspect it was linked to youtube url. I had the impression jsfiddle couldn't read this url : <!-- <iframe width="940" height="529" src="http://www.youtube.com/embed/rRoy6I4gKWU?autoplay=1" frameborder="0" allowfullscreen></iframe>-->
but with link get from share button on a youtube video, it worked. (july 2023)
For example, this worked :
<!-- <iframe width="560" height="315" src="https://www.youtube.com/embed/0AugFrZPP9U" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe> -->
jsfiddle link - poster for youtube video - with new youtube link