Everytime you open a video in Youtube, it starts to play in 360p definition or some other SD quality. If you want to watch the video in HD, then you can manually select the video quality from the video window itself. But this is very frustrating to do every time you want to play a video. If you are a Google Chrome user, then you can make use of the Auto HD extension for Chrome. The Auto HD for Youtube extension not only plays the Youtube videos in HD, but also allows you to widen the player.
After you have installed this extension in the Chrome web browser, you would notice a new icon in the toolbar (next to the address bar). You can click on this Auto HD icon to pull down the settings popup. In the settings, you can choose the video quality of the Youtube videos from 1024p, 720p, 480p, 360p and 240p. You should note that only 720p and 1024p are considered as HD. You can also choose whether you want to play the video in a wide player or normal size player.
For some reason, changing the quality setting does not work in just one attempt. You have to change the settings two times before it starts to work. After adjusting the settings to your like, you can visit Youtube website and start watching the videos in the HD or any other video quality that you have selected.
So if you want to watch Youtube videos in HD but are tired of adjusting the video quality over and over again, then just install the Auto HD for Youtube extension for Google Chrome browser and start enjoying Youtube uninterrupted.
You can download Auto HD for Youtube from https://chrome.google.com/webstore/.