Apple iPad uses Safari web browser. It supports HTML5, CSS3, and JavaScript. You can watch HTML5 h.264 videos on an iPad.

• YouTube
  You can use YouTube app to watch HTML5 videos from youtube. And you can use HTML5 version of YouTube.
  
• CNN
  When you’re browsing CNN.com on iPad, the site automatically displays an HTML5 video player, providing you with the best possible viewing experience.
  
• BBC News
  You can use BBC News app to watch news videos from BBC
  
• Reuters
  An HTML5 video player on Reuters.com lets you view most of the site’s video content on iPad.
  
• New York Times
  The HTML5 video player on the NYTimes.com home page displays video in a format viewable on iPad.
  
• Vimeo
  The popular video-sharing site Vimeo.com features an HTML5 player that displays most videos on iPad.
  
• Time
  The 24/7 news site features an HTML5 video player for viewing recently published video.
  
• ESPN
  ESPN uses HTML5 to play audio and video for fans browsing ESPN.com on iPad. Site navigation and live scoring have also been optimized for the iPad Multi-Touch display.
  
• Major League Baseball
  MLB.com features a browsing experience optimized for iPad, providing fans with live baseball action at their fingertips.
  
• Netflix
  The iPad-optimized version of netflix.com makes it easy to browse movies and add them to your queue. Video plays via the free Netflix app available on the App Store.
  
• NPR
  NPR’s website, NPR.org, incorporates an HTML5 audio player and embedded HTML5 video for iPad.
  
• National Hockey League
  NHL.com detects when you’re browsing the site on iPad and displays optimized content, including recently published video.
  
• The White House
  WhiteHouse.gov is a largely standards-based site that displays video using the HTML5 video tag.
  
• Sports Illustrated
  Recent video features on SI.com are displayed via an HTML5 player compatible with iPad.
  
• Flickr
  Flickr now displays video via an iPad-compatible HTML5 player.
  
• People Magazine
  An HTML5 video player on PEOPLE.com displays video in iPad-viewable format.
  
• TED
  TED.com is completely optimized for iPad, displaying video, comments, ratings, and more.
  
• CBS
  Watch clips from your favorite shows as well as recent full TV episodes of "Survivor" on the HTML5-enabled, iPad-friendly CBS.com.
  
• Spin
  SPIN.com features a browsing experience optimized for iPad, providing music fans with the latest live performances and backstage coverage of their favorite bands.
  
• National Geographic
  Watch National Geographic videos on your iPad using the new HTML5 player at nationalgeographic.com.
  
• ABC
  Play ABC videos with via the ABC Player app available on the App Store.