Export as Image
Maps can be exported as image. Tiled supports most common image formats. Choose File -> Export as Image… to open the relevant dialog.
Since exporting a map can in some cases result in a huge image, a Use current zoom level option is provided to allow exporting the map at the size it’s currently displayed at.
For repeatedly converting a map to an image, manually triggering this export
isn’t very convenient. For this purpose, a tool called tmxrasterizer
ships
with Tiled, which contrary to its name is able to render any supported map
format to an image. It is also able to render entire worlds to
an image. On Linux this tool can be set up for generating thumbnail previews
of maps in the file manager.