YouTube supports HD formats of 720p and 1080p, consistent with leading high-definition television sets currently on the market. By default, however, YouTube serves video in 480p, which is good enough for standard viewing in a browser window while limiting the bandwidth the video needs to render on your screen.
Activating HD for a Single Viewing
Within the YouTube video, click the gear-shaped icon to reveal menu options for annotations and quality. Click the Quality button and select the video resolution you want. Anything higher than 720p is considered high-definition, and the availability of high-definition video is dependent on the quality of the originally uploaded video.
In other words, if someone uploaded a video in standard definition, you can't force it into high definition.
Consider bandwidth when you're watching videos on a metered connection, like a cell tether. A 480p video requires 1 megabit per second (Mbps) of throughput to render; 720p can require 2.5 Mbps. Verizon Wireless suggests that the difference between standard and high-resolution video amounts to an additional 100MB of data use per hour against your contract limits.
Permanently Change Your Preferences
Current versions of YouTube only support a generic setting that uses the best available video resolution given your screen size and bandwidth.
On very fast connections, you may "default" to HD, but for some users, including digital subscriber line consumers, a mid-grade resolution may default instead.
To ensure that you get the best resolution for your hardware and network configuration:
- Log in to your YouTube or Google Plus account. You cannot set a permanent preference without being logged in.
- Click the round avatar in the upper right corner of the menu bar; when the menu flies out, click the gear icon.
- From the Account Settings screen, click the Playback menu option and then ensure that Always choose the best quality for my connection and player size is selected.
- Click Save to keep your changes. Use your browser's back button to return to YouTube.
You cannot set this resolution preference on a mobile YouTube app -- it's only supported within a desktop Web browser.