Bigger background images are automatically downscaled to a resolution of 1920×1080 at the upload.
If you want to use larger background images (e.g. for 4k displays) upload the image you intend to use into an image hoster (for example https://imgur.com) and use this CSS snippet to add it as a background image in your walls' settings:
body {
background-image: url(https://imgur.com/your_image);
}
You can find the custom CSS input field by selecting your wall, navigating to the "Settings" tab and clicking on "Design":
I've uploaded my image to imgur and my URL didn't work!
After the upload, your window looks like this:
Click on the image with the right mouse button and choose "open in a new window". Copy the URL of the new window. If done right, the URL should end with ".png", ".jpg" or ".jpeg" and ".webp".
In case you have further questions, don't hesitate to contact the support team via the chat or support@walls.io!