Firefox Community Forum

Hello people,

Please some help around the following issue, since a few days, Firefox will not play mp4 files directly in the browser. What it does when clicking to open an mp4 from the file server, it saves the file first and then opens a window to play it. Or it directly provides the save dialog window instead of playing it in the browser window directly.

Any ideas, appreciated. I have a lot of files to assess for my students, and this browser behavior makes it very tedious.

Greetings.

recently i have bought a membership on a website called anizium.com and there are 4k resulotion animes, my friends can watch them on 4k but i cant, they use chrome. After i downloaded chrome to check, and yeah i can watch them on 4k on chrome. Is there any solution to that bc i have been using firefox for years now and i dont wanna just use chrome to have 4k. Thanks to everyone who tries to help.

This issue came up in early April 2025.

Programs other than Firefox (e.g. Edge, Media Player) behave normally: when playing sound, if nothing is plugged into the 3.5 mm jack, the sound comes from the desktop's external speakers; and when an audio device (speakers or headphones) is plugged into the 3.5 mm jack, the sound instead comes from that device.

Where as Firefox will play using the internal speakers as expected, but when a device is plugged into the 3.5 mm jack, no sound signal goes to that device.

It seems then that the hardware is okay, and the problem must lie within Firefox, or within a Windows setting that is very specific to Firefox.

The sudden onset earlier this month may point to either a Firefox update, or (less likely) a Windows update.

We're finding we can no longer watch FUBO TV on Firefox. Works fine in Edge. Anyone have any suggestions? We've cleared cache/history, restarted laptop, etc. This occurs both on recorded programs and live tv. We still seem to be able to get the commercials, although we tried watching on two different devices and the commercials were very different. Is it possible for Firefox to have been hacked but not Edge on the same device? Doesn't sound plausible to me, but I'm not sure. This has happened since the last update to Firefox. We have Windows 10 64 bit. Firefox 134.0.2 or whatever the latest version is. We're stumped why it works on one browser but not the other. Has to be a Firefox issue.

I have installed a analog to digital converter software to convert High8 tapes to digital. It is all hooked up, but the video and audio from the converter program will no show on computer. Help!

Hello! For some time now I suddenly have no sound in Firfox, otherwise the sound works everywhere, even in other browsers. All help instructions do not help. Do I have to switch to another browser for good? Thanks for help

I don't get sound on any website, specifically NPR, Kanopy and Youtube. I've tried all of the suggestions in the Help menu, and they were, to put it mildly, no help. This seems to have begun with the latest update (134).

Following a recent update of my bios (AMD Ryzen) of my PC the on-board sound system failed. I chased down the issue, got a sound card to circumvent the on-board circuits, and had sound once again but for my FireFox (Ver 133.0.3, on Windows 11 Home, Ver 10.0.22631 Build 22631). Testing with alternate browsers (Edge, Opera) the sound works, as do my downloaded games and music but no joy with FireFox.

My question: Is this a known issue being addressed for a future update or are my circumstances an outlier issue?

MP4 Not loading:

I have uploaded a few MP4 animated images to our website, but they are not loading in the Firefox browser. It looks like they are getting corrupted. This issue only occurs in Firefox. I’ve also attached screenshots for reference. Can someone help me understand why they are loading like this?