Firefox Community Forum

Playback occasionally lags really hard for 1-2 seconds anytime I watch a video. This goes for all websites, not just youtube. It seems disconnected from buffering as it will happen even when the video is totally loaded. It doesn't lag out any other tabs, and switching to a different tab and back always fixes it (for that moment). I've already tried disabling hardware acceleration and webgl, but nothing changed. It happens about once every minute no matter what. I have a high-end pc, so that shouldn't be the problem. (or maybe it is, and firefox isn't optimized for some bit of hardware that I have) Thank you ^_^

Okay posted this into iOS but never got any proper help, so I'm guessing that was the wrong place to put this.

Whilst I'm watching a video, if said video is playing in fullscreen, it'll often fade to black during different parts, as whenever a flash happens or quick cuts (e.g. a film with lightning strikes, causes it to fade to black and it stays like that - then fades back in super slowly). It is SUPER annoying and it causes me to have to rewind if I miss something because of it (only for it to do it again and again)! I don't watch YouTube in fullscreen because of it, but it even does it in streaming services - but worse! I honestly have had enough of this, it is genuinely infuriating.

I'm on MAC air 2022 M2, macOs Tahoe 26.6.2 - and the most recent up-to-date Firefox update: Version 157.0 I usually put off updating Firefox because it signs me out of everything! Meaning I have to resign into all of my school things, streaming, YouTube, and even this page itself!

Now I've gone into a private window and tested it to see if it does the same thing - yes, yes it does do the same thing, I put on the same two YouTube videos and it did the exact same fading in the middle of it at the same exact timestamp!

Took this photo of the movie Cruella because I knew there was loads of flashing lights at one scene. You can see that the video is faded but the rest isn't. The second image is when I click multiple times to try and stop it! But it happens again directly after.

Please help me, this is really annoying and I've put up with it for too long :(

I just upgraded Firefox to version 156.0.2.

It no longer plays mp4 content from a website. It says "No video with supported format and mime type found".

This used to be OK.

My computer just updated Firefox. Since that happened I can't stream a movie in full screen. That is, I can make the window as big as the screen, but I can't hide the tabs, time and date, pull down menu titles, etc, I want to see nothing but the movie. On Netflix you typically do this by clicking on the rectangle in the bottom right corner. But now nothing happens when I click on this. Can you help with this?

Thank you

I uploaded an image to show what I mean, but nothing is showing next to the words Uploaded images.

I'm not sure when it started happening, but whenever I'm watching something full screen, or just full screening, Firefox on Mac, there's this thin white line at the top of the window that's very distracting. Has this been happening to anyone else and does anyone else know how to get rid of it?

All of a sudden all of the videos I watch on YouTube with Firefox are defaulting to mute on my Macbook. I haven't made any changes to settings, etc. I don't have a YouTube account so I can't make any changes there anyway. I am having to unmute each video before I watch it.

Здравствуйте!

Столкнулся с проблемой при просмотре видео на YouTube в Firefox на Windows 11.

При переходе видео в полноэкранный режим панель задач Windows не скрывается и остаётся видимой поверх/под окном браузера. В других браузерах, например Google Chrome, такой проблемы нет.

Единственный способ временно решить проблему — нажать F11 и перевести сам Firefox в полноэкранный режим, однако это неудобно, поскольку я часто переключаюсь между вкладками и сворачиваю/разворачиваю браузер.

Проблема возникает именно при использовании стандартного полноэкранного режима YouTube.

Я могу предоставить все необходимые диагностические данные: сведения о системе, версии Firefox, настройки `about:config`, логи, скриншоты или любую другую информацию, которая может помочь определить причину.

Подскажите, пожалуйста, как можно диагностировать и исправить эту проблему?

Спасибо!

I checked the parameters:

full-screen-api.ignore-widgets = false browser.fullscreen.autohide = true

I restarted File Explorer, the browser, and the PC; the problem only occurs in Firefox. At the same time, if I press F11 in advance, then when I press F again or open a full‑screen video with the mouse, the taskbar no longer interferes. I tried running the video in incognito mode, but the problem persists.

Hello, this is the basic problem:

The short version is that there is a problem with Firefox not interacting with the scrub bar and volume bar. (all other controls work fine) We know it's a Firefox thing because everything works with Brave. (or an interaction between Firefox and the OS at least, Firefox is heavily involved)

There is more detail and we have done some work on it here: CashyOS forum post

You can use the Firefox manifesto V0.2. video for an example, as it displays all the above problems for me.

I can get you guys whatever other data might be needed, but I kinda need an idea where to look to try and fix this, as all the other posts I have managed to find don't seem to have similar enough issues to work.

Edit/Update: I have done some further testing and discovered that it is firefox's default/built in player that is the problem. I can use the 'site specific' players (like from reddit) just fine. So there is something happening with that default one.

YouTube videos are frequently buffering and sometimes play slowly in Firefox, even when my internet connection seems to be working normally. Please help me identify the cause and suggest steps to fix the problem. I would also like to know whether any Firefox settings, extensions, cache, or hardware-acceleration settings could be causing this issue.

You can write:

YouTube videos are frequently buffering and sometimes play slowly in Firefox, even when my internet connection seems to be working normally. Please help me identify the cause and suggest steps to fix the problem. I would also like to know whether any Firefox settings, extensions, cache, or hardware-acceleration settings could be causing this issue.