With the new look, YouTube wants to make it easier for users to find the channels they love and "subscribe, subscribe, subscribe".
The Google-owned online platform now has the same cleaner and simpler design as recently introduced to apps like Google+ and Google Now, involving a white and grey colour scheme and sparser layout.
"You come to YouTube to watch the videos you care about, so it's important that the videos stand out," said YouTube in a blog post.
"In this new layout, you'll find the most crucial elements are front and centre when you watch a video: the video is right at the top of the page and the subscribe button, social actions and video information are all combined directly below the player."
Playlists are now available to the right of videos, allowing the user to continue browsing other videos while they watch.
Last year, YouTube enabled its users to subscribe to channels via a Guide on the homepage. This meant that they were alerted when new content was available to watch from providers such as Jay-Z, WWE and The Onion.
The original channels first launched in the US, but have since expanded internationally on YouTube.
Now, YouTube has introduced the subscription-filled Guide across the website and all the hundreds of millions of devices where it is available, including Android, iPhone, Playstation 3, Google TV and more.
Users can subscribe to their favourite channels and the Guide will let them know when there are new videos waiting to be watched.
The system will also suggest other channels that the user may enjoy and show what their friends are sharing across the web.
YouTube has invested heavily in introducing more original content channels to the site, as it looks to become more of an online entertainment portal, as well as a place to watch user-generated short-form videos.
The redesign is aimed at making it easier for people to discover and subscribe to more original channels. This will encourage more content providers to get on board and also help YouTube drive up its advertising revenues.
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