YouTube on Safari is low res and grainy; same video on YouTube on Chrome is crystal clear

Hey there!

I’d first check your YouTube settings in Safari while on the web site, this article is provided by YouTube:

Change the quality of your video:

https://support.google.com/youtube/answer/91449?hl=en

A previous question was does the same happen on other web sites. If it does NOT, then I’d either check out that web site above, or check out your Safari web site preferences:

Change Websites preferences in Safari on Mac:

https://support.apple.com/guide/safari/websites-ibrwe2159f50/mac

If the same DOES happen for other websites that play videos, and the website preferences don’t appear to have any reason for this:

Check Safari Extensions:

Safari > Preferences > Extensions.

Disable or uninstall all, relaunch Safari and test.

Also, either clearing Safari’s history and/or website data and relaunching is a good step.

If this issue is specific to YouTube:

Open Safari > Preferences > Privacy > Manage Web Site Data, search or find YouTube > Select > Remove. Relaunch Safari and test.

Otherwise, specially if happening on more than one website, I may clear Safari’s history:

Safari > Clear History > All History. Relaunch and test.

I've had similar issues with YouTube, and what I've discovered is that whenever a sidebar is open (such as "Watch Later" or another playlist), it will hinder performance. I don't know why that happens, but closing or hiding that sidebar resolves my performance issues with YouTube and Safari.

Hello Chris,

Welcome to Apple Support Communities. We understand that you're having some issues with video quality on the Youtube site when using Safari.

Do videos on other websites in Safari have any quality difference as opposed to your Chrome browser? That might help to isolate whether this issue is with Safari or the website. Try the steps from If Safari doesn't open a webpage or isn’t working as expected.

Take care.

What version of macOS are you using? If you are using an older version of macOS, then Safari may be too outdated to work properly now since once Apple stops supporting macOS Safari also stops receiving updates for that OS.