Reddit banner size

1920 × 384 for a subreddit banner — a 5:1 strip. Mobile shows a considerably narrower slice of it, so keep anything readable in the middle half.

At 5:1 this is one of the most extreme aspect ratios of any placement, and mobile makes it worse by showing only a central portion. A subreddit name that reads perfectly on desktop can be entirely off-screen on a phone, where the majority of Reddit traffic is. Design it as a texture or a simple centred wordmark rather than a layout. The icon is masked to a circle, and unlike the banner it is shown at a consistent size everywhere, which makes it the more reliable place to put identity.