Issues with YouTube showing horizontal scroll bar when attempting to watch fullscreen

Resolving the Horizontal Scrollbar Issue in YouTube Videos When Transitioning to Fullscreen

Many users have encountered a peculiar and disruptive problem while watching videos on YouTube: a horizontal scrollbar appearing at the bottom of the video player when switching to fullscreen mode. This issue can significantly detract from the viewing experience, causing unnecessary distraction and frustration.

Understanding the Issue

The unwanted horizontal scrollbar typically manifests as a thin line beneath certain YouTube videos, particularly noticeable at the bottom of the video player. When attempting to enter fullscreen mode, instead of expanding seamlessly, viewers might see this scrollbar, which indicates that the video or its container is slightly wider than the viewport.

Common Causes

Several factors may contribute to this issue, including:

• CSS or layout conflicts: Custom themes or browser extensions can interfere with YouTube’s default styles.
• Browser zoom levels: Running the browser at non-standard zoom levels may cause layout discrepancies.
• Outdated browser or plugins: Compatibility issues with outdated software can lead to rendering problems.
• YouTube UI changes or glitches: Occasionally, updates from YouTube itself might introduce bugs affecting display.

Recommended Solutions

To address this problem, consider the following troubleshooting steps:

1. Reset Browser Zoom Settings
   Ensure your browser zoom is set to 100%. You can usually reset zoom by pressing Ctrl + 0 (Windows) or Cmd + 0 (Mac).

2. Update Your Browser
   Use the latest version of your preferred browser to ensure compatibility and fix known bugs.

3. Disable Browser Extensions
   Temporarily disable extensions, particularly those related to video playback, ad-blocking, or CSS modifications, to identify if they are causing conflicts.

4. Clear Cache and Cookies
   Sometimes, cached data can cause rendering issues. Clearing your browser cache may help resolve the problem.

5. Check for Custom Themes or User Styles
   If you are using custom CSS or themes, review them for potential conflicts with YouTube’s layout.

6. Try Incognito or Safe Mode
   Open YouTube in a private or incognito window to see if the issue persists without extensions or customizations.

7. Adjust Video Player Size with Developer Tools
   Advanced users can inspect the page using browser developer tools to identify and correct CSS anomalies causing the scrollbar.

When the Issue Persists

If none of the above solutions resolve the problem