YouTube appears to be testing out a new video player feature which will dynamically change the player's dimensions, depending on the user's browser window's size. For instance, when a Chrome page is resized, YouTube changes from 360p to 480p and to 720p, and the video player gets bigger. This experiment is testing the automatic responsive design of the player which means that users won't need to do a thing.

With the new dynamic design you can see the same video in a larger player (480p) and an almost fullscreen player (720p) on a 1080p display:



The Google Operating System Blog screenshots the fact that YouTube's "stats for nerds" feature confirms the size of the player and the video resolution:


Want to test out the new experiment for yourself? If you're a Chrome, Firefox, Opera, Safari or Internet Explorer 8+:

#1: Open in a new tab.

#2 Load your browser's developer console:

  • Chrome or Opera 15+ - press Ctrl+Shift+J for Windows/Linux/ChromeOS or Command-Option-J for Mac
  • Firefox - press Ctrl+Shift+K for Windows/Linux or Command-Option-K for Mac
  • Internet Explorer 8+ - press F12 and select the "Console" tab
  • Safari 6+ - if you haven't enabled the Develop menu, open Preferences from the Safari menu, go to the Advanced tab and check "Show Develop menu in menu bar". Close Preferences and then press Command-Option-C to show the console.
  • Opera 12 - press Ctrl+Shift+I for Windows/Linux or Command-Option-I for Mac, then click "Console".

#3 Paste the following code which changes a YouTube cookie:

document.cookie="VISITOR_INFO1_LIVE=E_OLzg3yeLw; path=/;";window.location.reload();

#4 press Enter and close the console.

To go back to the regular interface, use the same instructions, but replace the code from step 3 with this one:

document.cookie="VISITOR_INFO1_LIVE=; path=/;";window.location.reload();

H/T to Google Operating System blog for the heads up and the images.