How do I fix Facebook Reels with no sound in my browser when other sites play audio?

If everything else has sound, start with Facebook and the browser rather than your speakers. Unmute the Reel in its player, then check that the Facebook tab or site hasn’t been muted. In Chrome, go to Settings > Privacy and security > Site settings > Sound and make sure Facebook isn’t blocked; Firefox can also block audio autoplay for a specific site. Then reload Facebook, try it in a private window with extensions out of the way, and update the browser. Meta’s own playback steps also recommend an up-to-date Chrome, Firefox, Safari, or Edge and a computer restart. If it’s still only Facebook after that, report the problem from Facebook’s Help & support menu.