I love to load videos up from the web inside QuickTime Player so that I have more control over pausing and resuming them and they don't get lost amongst 100 browser tabs.
1. First, you need to get the location of the video. HTML5 videos expose their location. Locate the video you want. In this case, we're going to look at the WatchKit Developer Page.
2. Now click the thumbnail image on the website to play the video.
3. Position your mouse over the video and Right Click > Inspect Element
4. Drill down inside the contents of the HTML code for the video by clicking on the expander triangle
5. Right Click on the video URL and select Copy Link Location. Alternatively double-click on the URL to enter edit mode and copy the text as you normally would. Just be aware you might have extra characters like " or ) that you have to clean off the end.
6. Open up QuickTime Player on your Mac. Press ⌘L (or File > Open Location)
7. Paste the URL and click Open
8. Now you have the video playing on your computer.
Bonus! Now if you really want to be fancy speed that puppy up to 2x playback so you can get done and on to the next one in no time flat.