Make YouTube Video Embeds Responsive Using Pure HTML and CSS

Zach Zach (235)
Total time: 2 minutes 

Surprisingly, normal YouTube embeds are not automatically sized to the browser window as it is resized. Luckily, you can make YouTube videos responsive and mobile-friendly with some simple HTML and CSS.

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Wrap your embed code in a unique video wrapper (the class name is arbitrary). I chose to use embed-youtube as the selector.

<div class="embed-youtube">
    <iframe src="//" width="750" height="563"></iframe>

We'll use a CSS "padding trick" to maintain the video's aspect ratio as the browser is resized. Add the following to your stylesheet:

.embed-youtube {
    position: relative;
    padding-bottom: 56.25%; /* - 16:9 aspect ratio (most common) */
    /* padding-bottom: 62.5%; - 16:10 aspect ratio */
    /* padding-bottom: 75%; - 4:3 aspect ratio */
    padding-top: 30px;
    height: 0;
    overflow: hidden;

.embed-youtube iframe,
.embed-youtube object,
.embed-youtube embed {
    border: 0;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;

Most YouTube videos use an aspect ratio of 16:9; therefore, I recommend using a value of 56.25% for the padding-bottom property, as noted above. To calculate other aspect ratios, simply divide H/W. For example, let's say you have a video with an aspect ratio of 4:3. Dividing 3÷4 equals 0.75, or 75%. Therefore, padding-bottom would be 75% to maintain this aspect ratio.

Resize your browser window and bask in the responsive glory.