preload

audio - This enumerated attribute is intended to provide a hint to the browser about what the author thinks will lead to the best user experience. It may have one of the following values:

• none: indicates that the audio should not be preloaded;
• metadata: indicates that only audio metadata (e.g. length) is fetched;
• auto: indicates that the whole audio file could be downloaded, even if the user is not expected to use it;
• the empty string: synonym of the auto value.

If not set, its default value is browser-defined (i.e. each browser may have its own default value). The spec advises it to be set to metadata.

Usage notes:

• The autoplay attribute has precedence over preload. If autoplay is specified, the browser would obviously need to start downloading the audio for playback.
• The browser is not forced by the specification to follow the value of this attribute; it is a mere hint. video - This enumerated attribute is intended to provide a hint to the browser about what the author thinks will lead to the best user experience. It may have one of the following values:
• none: indicates that the video should not be preloaded.
• metadata: indicates that only video metadata (e.g. length) is fetched.
• auto: indicates that the whole video file could be downloaded, even if the user is not expected to use it.
• the empty string: synonym of the auto value.

If not set, its default value is browser-defined (i.e. each browser may have its default value). The spec advises it to be set to metadata.

Usage notes:

• The autoplay attribute has precedence over preload. If autoplay is specified, the browser would obviously need to start downloading the video for playback.
• The specification does not force the browser to follow the value of this attribute; it is a mere hint.