In the sheet's CSS file you should see something like: .charsheet .sheet-main { background: url(<a href="https://imgsrv.roll20.net/?src=https%3A//raw.githubusercontent.com/Roll20/roll20-character-sheets/master/Shadow%2520of%2520the%2520Demon%2520Lord/Assets/main_bg.jpg" rel="nofollow">https://imgsrv.roll20.net/?src=https%3A//raw.githubusercontent.com/Roll20/roll20-character-sheets/master/Shadow%2520of%2520the%2520Demon%2520Lord/Assets/main_bg.jpg</a>); background-repeat: no-repeat; background-position: center center; background-size: cover; height: 1139px; width: 880px; } You just need to swap out the URL .charsheet .sheet-main { background: url(<a href="https://i.imgur.com/YgdFbIT.jpeg" rel="nofollow">https://i.imgur.com/YgdFbIT.jpeg</a>); background-repeat: no-repeat; background-position: center center; background-size: cover; height: 1139px; width: 880px; } That will give you this: Be aware, the other tabs have different background images (or at least different than the Main tab), so you'd need to replace those URLs, too. But you should be able to find them simply by searching for http:// and then finding the ones associated with background or background-image, etc.