I'm running Chrome on my Mac and all of a sudden videos started playing in the HTML5 player instead of the Flash player.

I am not in the HTML5 trial, the button says Join instead of Leave and I have tried joining and leaving to try and toggle something but that hasn't worked. I have even tried adding &html5=false to the end of the URL and not even that has seemed to work.

Has anyone any idea how to switch it back to Flash Player?

  • What indicates that the videos are playing in HTML5? Oct 22, 2013 at 7:32
  • 2
    Upon right clicking the video, it displays the HTML 5 menu with one of the options being "About HTML 5" Oct 22, 2013 at 7:50
  • 2
    Even worse, HTML5 elements are not affected by Chrome’s click-to-play function, so there is no way to prevent Youtube videos from automatically loading, buffering, and playing. There are some extensions that can help with this, but they don’t work with Youtube’s Feather mode. ಠ╭╮ಠ
    – Synetech
    Nov 22, 2013 at 20:00
  • 2
    Here's how I enforced my dominion over Chrome: Find the file called ffmpegsumo.dll where Chrome is installed (C:\Program Files (x86)\Google\Chrome\Application\30.xxxxx\ for me). Delete it or move it out of that folder. I also moved nacl_irt_*.nexe. Nov 27, 2013 at 21:28
  • @wizlb Where would the file be located on Mac? Dec 3, 2013 at 1:07

7 Answers 7


You can use the YouTube Options extension for Chrome:

enter image description here

Update (2014-04-12): the YouTube Options extension for Chrome now costs $2:

"YouTube Options" cost $2.00 per month, below is a copy of the user agreement one has to confirm prior to using it.

This extension is based on a paid subscription model. It costs a flat fee of $1.99 per month, with half of all proceeds going to non-profit organizations. Why the monthly fee? YTO is a fully supported, ever-evolving product and half of the subscription fee goes toward sustaining the level of effort needed to develop quality software. But we’re not just trying to make our product better — we’re trying to make the world better, too. The other half of the subscription fee is donated to causes we believe in. Visit the SPOI site to learn about the charities we are supporting this year. For more information on the ways you can customize your YouTube experience, explore the options here, or get the full list of more than 120 configuration options on the YouTube Options site. Until you purchase a subscription license using PayPal, YouTube Option’s functionality will be disabled.

Which means I won't use it anymore.


I found a solution here: https://groups.google.com/forum/#!topic/mozilla.dev.extensions/0ZgKDAFfUDc

Here's how I disabled HTML5 video in Chrome on Windows: Find the file called ffmpegsumo.dll where Chrome is installed (C:\Program Files (x86)\Google\Chrome\Application\30.xxxxx\ for me)

Worked for me as well, but after a while the html5 player returned. Maybe we will have to remove this file each time Chrome is updated.


I had this problem but like you lot all the fixes on the web either are payed for or ffmpegsumo.dll always comes back after a period. I have now fixed mine permanently and here is how I did it.

This is for a Windows based Computer

  1. Find the ffmepegsumo.dll you should all know where it is located.
  2. Right click on it and Choose properties then Choose the Security tab
  3. Click the first user account usually SYSTEM then Click on the edit button. In new window put a tick in all boxes under the heading DENY Click apply Click OK
  4. Do the same thing for all the other users of the computer
  5. Delete the ffmpegsumo.dll

Reboot the computer and thats it ffmpegsumo.dll will never come back because the computer will now not allow it

  • Interesting. If I was on a Windows machine I'd definitely try that! But, problem is my main computer is a Mac Nov 5, 2014 at 13:09
  • I don’t think that will work. Once you delete the file, its ACL goes with it.
    – Synetech
    Jul 8, 2015 at 3:52

Here is an extension that forces Flash on YouTube (tested on 02/05/2015).

Also, to remove the annoying fullscreen message type in the address bar: chrome://plugins/, find: "Adobe Flash Player" and check the box next to Always allowed.


Finally found a fix! So simple I wonder why I never thought of it in the first place..

Simply deleting all the cookies that youtube.com has saved switched me back to the flash player.

My best guess is that when it came time to opt-out from the HTML5 trial the cookie was never properly cleared or set back to flash.

  • It's just reverted back to HTML5 again and a cookie clear won't do anything anymore -.- Jan 15, 2014 at 1:52

If you're using Chrome on OSX, Go to the Application folder, right click on "Google Chrome" click on "Show Package Contents" then navigate to Contents/Versions/{version-number}/Google Chrome Framework.framework/Libraries.

Then rename or delete the .so file that contains ffmpeg in the name. Restart Chrome

If your using Chrome on Windows 8: Navigate to Program Files/Google/Chrome/Application/{version-number}/ and rename or delete ffmpegsumo.dll

Restart Chrome

After completing the above if you right click on a youtube video you'll see that it uses the flash player version.

The only issue with the above is that whenever Chrome has an update the ffmpeg file will be restored, so you'll need to repeat the above steps.


Override your UserAgent string to some older browser, like Firefox 4 or IE8, and reload the page.

  • Your answer is a bit scarce on details to be good. You might get more upvotes if you include a more detailed description of what to do. Jan 7, 2015 at 13:19
  • Actually, I think it should work a treat. Google, in its infinite arrogance and fascist dilettantism has, as usual, assumed users are idiots who cannot decide what is good for them and dictated what is best for users. As such, they made it so Chrome/Chromium are forced to use the HTML5 player by not providing an opt-out function in the YouTube HTML5 page. However, the option is present when viewed in other browsers. Therefore, spoofing the UserAgent to trick YouTube into think you’re using a different browser should restore the opt-out option.
    – Synetech
    Jul 8, 2015 at 4:01

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