Safari youtube fullscreen glitch

Hey guys, I have just found a fix for that, I had exact same issue on ma 2017 mbp, and what's causing it's the screen scaling feature which you turn on in "my Mac> displays, you have to keep it in normal, not scaled mode -,- I have checked it at apple store, and all Macs there with that scaling mode turned on had the same issue, when you turn the scaling into "default" it only flickers like for half a sec and then plays normal, the same with all three Macs at apple store. It is a problem with graphics compatibility but it seems that all Macs with newer Sierra have that issue. cheers

I have found a temporary solution.

It's not perfect but will help until they find the real solution:

basically what it does is that it does not let the youtube control panel to disappear 🙂

what you do is bring the cursor to the volume button, the cursor will change to "finger" from an "arrow"

keep the cursor there don't move and enjoy the video 😉

Try upgrading to 10.13.3 to get Safari 11.0.3.

Try running the combo update. It installs all previous updates plus the new one, which can replace any files that may have become corrupted.

Download macOS High Sierra 10.13.3 Combo Update - Apple Support

Try setting up another admin user account to see if the same problem continues. If Back-to-My Mac is selected in System Preferences, the Guest account will not work. The intent is to see if it is specific to one account or a system wide problem. This account can be deleted later.

Isolating an issue by using another user account

If the problem is still there, try booting into the Safe Mode using your normal account. Disconnect all peripherals except those needed for the test. Shut down the computer and then power it back up after waiting 10 seconds. Immediately after hearing the startup chime, hold down the shift key and continue to hold it until the gray Apple icon and a progress bar appear. The boot up is significantly slower than normal. This will reset some caches, forces a directory check, and disables all startup and login items, among other things. When you reboot normally, the initial reboot may be slower than normal. If the system operates normally, there may be 3rd party applications which are causing a problem. Try deleting/disabling the third party applications after a restart by using the application un-installer or by using the developer’s uninstall instructions. For each disable/delete, you will need to restart if you don't do them all at once.

Safe Mode - About El Capitan
also Sierra

Safe Mode Startup – El Capitan. also Sierra

If it works in the Safe Mode, try running this program when booted normally and then copy and paste the output in a reply. The program was created by Etresoft, a frequent contributor. Please use copy and paste as screen shots can be hard to read. On the screen with Options, please open Options and check the bottom 2 boxes before running. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown.

Etrecheck – System Information

I also have this problem, only came to light after the latest High Sierra upgrade to 10.13.4.

I have a MacBook Air 10.1 and its a standard spec MacBook (128GB storage and 4GB of ram).

Previously sometimes going to full screen would be a black screen with the audio playing. suiting safari and restarting safari would temporarily fix the issue.

Now after the latest update the full screen video will be chopped at a 45 degree angle with the video split (video is on a slant) but only after the on screen controls for youtube disappear.

However a work around. Once I select full screen, I move the mouse to the bottom of the screen and as long as the dock is present then the full screen video plays fine.

This only happens with video that is 720p, not with lower quality video.

I suspect this is a codec issue and not user dependant (I have tried another user on the same MacBook and the issue still happens).

The version of safari is 11.1 and only seems to happen on the 10.1 inch MacBook. the wife's 13 inch MacBook is not affected by this.

I can confirm his information.

I have the same problem on a 2018 15inch MacBook Pro.

Turning off extensions and all that stuff did not resolve the problem.

However, when I turn off Automatic Graphic Switching, the problem is gone. I therefore assume that it has something to do with the integrated Graphics.

I solved this issue by going to Safari/Preferences/Advanced and unchecking "Stop plug-ins to save power."

I just started having this problem today. I noticed when I clicked on Show Sidebar, the missing full screen controls re-appeared. If I closed it they were gone again. Also going into full screen before they disappeared didn't last, it just switched right back.

So I turned on the sidebar and entered full screen, which persisted. After I exited full screen mode, and closed the sidebar, the issue went away. Weird.

Hi Bert,

I was experiencing this same issue and I opened a support ticket. They recommended to upgrade to the recently released IOS Mojave and it seems to have fixed that problem.

You can download it here:

Get macOS Mojave

I had the very same issue on Sierra and High sierra. See my bug report at webkit: https://bugs.webkit.org/show_bug.cgi?id=172762

With Mojave the video started to lag in fullscreen: https://www.youtube.com/watch?v=BgnsH2DPBfI So I think this bug is not completely fixed.

I'm pretty sure that it is related with multiple user accounts on the Mac and sleep as I have similar setup.

I have several bugreports at https://bugreport.apple.com/:

45843181, 35436479, 36128807, 41193728

I hope Apple will be able fix this bug as it haunts me for 2 years. Until that you can use Chrome or Firefox as they have no issues with fullscreen videos.

Ps.: I have Macbook Air.

Hi,

You may have a third party Safari extension or plug-in installed that's causing a conflict when the routine update was installed.

Troubleshooting help here > If Safari is slow, stops responding, quits unexpectedly, or has other issues - Apple Support

I have the same issue. For me, when I watch full screen on Youtube, the images get pixelated quite a bit, especially in dark areas of the screen. However, when I move the mouse so that control panel appears, the screen becomes normal. Pretty much the same thing happens on Netflix as well. If you watch the same clips on Firefox, everything is normal. Pretty sure this has to do with "Automatic graphics switching" function; I'm suspecting issues with integrated GPU...Apple, please fix this...

You are welcome. Clarification question - you tried in another browser and it worked?

Since it was the same in another user account, it seems to be a system wide problem. I can't think of anything else to check. As a last resort, you could try doing a backup, preferable 2 separate ones on 2 drives. Boot to the Recovery Volume (command - R on a restart). Run Disk Utility and select First Aid. Then re-install the OS.

OS X Recovery

OS X Recovery (2)

I have the same exact issue with Safari, this also happens when watching Netflix fullscreen too. Hoping for a fix, just updated to 10.13.4 and the problem persists. Chrome works just fine.

Using base model MacBook Air 11-inch, Early 2015.

I went in to my display settings and changed my resolution to 1280 x 720 this seems to have worked for Netflix haven’t tried YouTube yet hopefully this can be a temp solution until a permanent one can be figured out.