Mozilla says that Firefox 47 brings improvements to Youtube video playback, among other new features.
If you have a powerful multi-processor computer, Firefox promises to deliver an "improved video experience" when viewing videos on YouTube. This means videos will run smoother. You will also use less bandwidth and get improved battery life on your laptop.Mozilla is also making it easier to access synced tabs directly in your desktop Firefox browser. If you’re logged into your Firefox Account, you will see all open tabs from your smartphone or other computers within the sidebar. In the sidebar you can also search for specific tabs quickly and easily.
And if you are an Android user, Mozilla engineers have removed the icons that show up in the URL bar. This prevents unsecured sites from copying the images of legitimate sites to try to trick you into thinking the site is safe for sensitive information.
Lastly, Firefox for Android is getting a feature that lets you show or hide web fonts. This may reduce the amount of data required for browsing, an important factor for data-conscious users.