The minimum dimension for the Banner Image upload should be 2048 x 1152 with an aspect ratio of 16:9.The file size should be 6MB or smaller
Add or remove Banner Image on YouTube
On your YouTube page, click the object of the Profile Picture. In the drop-down menu. Click Your Channel; it will take you to the Your Channel Page.
On Your Channel page, on the left, click on Customized Channel; this will take you to the Channel Customization Page.
On the Channel Customization Page, Click Branding. Where you see Banner Image, click Upload. A File Upload dialog box will appear. In the File Upload dialog box, select the file you want, then Open.
A Customize Banner Art dialog box will appear displaying the picture. Click Done.
Click, Publish. Now we have a Banner Image. To remove the Banner Image, click Remove, then Publish. That’s it. Read next: How to Add or Remove Watermark on YouTube videos.
