Videos will not play in Galaxy phone or tablet's browser

Navigate to and open Settings, and then swipe to and tap Software update or System updates. It will vary between models.

Tap Download and install, Check for system updates, or Check for software updates, depending on your carrier. If an update is available it will begin downloading automatically, although you may need to tap Download now on some devices

Next, check for app updates using the Play Store or Galaxy Store:

• Play Store: Open the Play Store, then tap your profile icon in the top right corner, and then tap Manage apps & device. Tap Updates available (if it appears), and then tap Update all.
• Galaxy Store: Open the Galaxy Store, then tap Menu, and then tap Updates. Tap Update all.

Although the permissions for JavaScript are turned on by default, the setting may have been accidentally disabled.

• Samsung Internet: Open Samsung Internet, then tap the Tools menu, and then tap Settings. Tap Sites and downloads, then tap Site permissions, and then tap the switch next to Allow JavaScript.
  
  
  
  
• Google Chrome: Open Chrome, then tap More options (the three vertical dots), and then tap Settings. Tap Site settings, then tap JavaScript in the Content section, and then tap the switch.
  
  

Swipe down from the top of your phone’s screen using two fingers to open the Quick settings panel, and then touch and hold the Wi-Fi icon. Make sure you are connected to a network under Current network. If not, select a network under Available networks and enter the password if necessary.

• Samsung Internet: Open Samsung Internet, then tap the Tools menu, and then tap Settings. Tap Personal browsing data, then tap Delete browsing data, and then select Cookies and site data and Cached images and files. Tap Delete data, and then tap Delete when prompted.
  
  
  
  
• Google Chrome: Open Chrome, then tap More options (the three vertical dots), and then tap Clear browsing data. Tap the drop-down menu to select your desired setting (such as Last 15 minutes or Last 24 hours), and then tap Clear data.
  
  

You can use Device care to optimize your phone’s battery, storage, and memory. Navigate to and open Settings, then tap Device care, and then tap Optimize now. Tap Done.