The preload attribute specifies if and how a media file is loaded after the page loads.
Elements that accept this attribute include <audio> and <video>.
A preload attribute on an <audio> player.
The preload option is none. The audio file is only loaded when the start button is clicked.
<audio controls preload="none">
<source src="/media/epic.mp3" type="audio/mpeg">
<source src="/media/epic.wav" type="audio/wav">
</audio>
For additional details see our HTML audio preload Reference.
The preload attribute specifies how an audio or video file is loaded after the page loads.
This attribute can specify that the audio or video file is loaded even if the user does not need it.
The preload setting is ignored when autoplay is enabled.
Tip:
This page presents preload on <audio> and <video> elements.
However, the <img> element has its own preload settings,
as do <link> elements with rel="preload".
<tagname preload="auto | metadata | none">
| Value | Description |
|---|---|
auto |
Loads the entire audio or video file when the page loads. |
metadata |
Only audio or video metadata is loaded when the page loads. |
none |
Does not load the audio or video file when the page loads. |
empty string |
Assigning no value is the same as the auto setting. |
Note: Each browser has its own default value for preload.
For consistency the metadata setting is a reasonable option.
The following elements accept the preload attribute.
| Elements | Description | |
|---|---|---|
| <audio> | Creates an audio player -- see example above | |
| <video> | Creates a video player |
A <video> tag with an preload attribute.
The video file is only loaded when the start button is clicked.
<video width="320" controls preload="none">
<source src="/media/movie.mp4" type="video/mp4">
<source src="/media/movie.ogg" type="video/ogg">
</video>
For additional details see our HTML video preload Reference.
Here is when preload support started for each browser:
 Chrome
|
4.0 | Jan 2010 |
 Firefox
|
4.0 | Mar 2011 |
 IE/Edge
|
9.0 | Mar 2011 |
 Opera
|
11.5 | May 2011 |
 Safari
|
4.0 | Jun 2009 |
