What YouTube says about banner images
A minimum of 2048×1152 at 16:9, a recommended 2560×1440, a safe area of 1235×338 at the minimum size, and a 6 MB limit.
These are the figures on YouTube’s help page about channel branding. It lists a minimum dimension for upload of 2048×1152 pixels at 16:9, a recommended dimension of 2560×1440 (especially for TV), and a safe area for text and logos of 1235×338 pixels at the minimum dimension. It adds that images should accommodate the entire screen on larger devices but will be cropped on certain views and devices, asks you not to add shadows, borders or frames, and sets the file size at 6 MB or smaller. Source: YouTube Help, manage your channel branding. Checked against the platform’s own help page on 6 October 2026.