How to use YouTube Thumbnail A/B Previewer

• 1Click the 'Replace Image' box on the left to upload your drafted thumbnail (16:9 ratio recommended).
• 2Type your intended video title into the text box to see how it naturally breaks across multiple lines.
• 3Adjust the channel name, views, and timestamp to replicate a real-world scenario.
• 4Toggle between Light Mode and Dark Mode at the top to ensure your thumbnail maintains high contrast and visibility regardless of the viewer's device settings.