This table lists the preload behavior of different browsers and devices that support HTML5, at different settings of the preload attribute. For every setting and browser, we have indicated if the preload tag is followed.
|Firefox 25||works||1.2 MB loaded|
|Chrome 30||works||2.5 MB loaded|
|Safari 6||works||75 MB loaded|
|Internet Explorer 9||-||75 MB loaded|
|Internet Explorer 10||works||5.7 MB loaded|
|Internet Explorer 11||works||5.7 MB loaded|
|iOS 6 (iPad)||works||0 MB loaded|
|iOS 7 (iPad)||works||0 MB loaded|
|Android 4.0 (Browser)||works||0 MB loaded|
|Android 4.2 (Chrome)||works||0 MB loaded|
|Android 4.2 (Browser)||works||0 MB loaded|
|Android 4.4 (Chrome)||works||0 MB loaded|
See the HTML5 preload spec for a description of preload options and desired behavior.
Our test video is 15:00 at 270p. For Firefox and Opera, we use this encode (WebM, 75MB). For the other browsers and devices, we use this encode (MP4 75MB). Here is the tag with preload=none attribute:
And here is the test tag without preload attribute:
For obtaining data, we proxied each browser and device through the Charles web proxy:
- Chrome, Firefox, Internet Explorer and Safari are automatically proxied by Charles.
- iOS and Android both have proxy options in their WiFi settings.