Assert-env is a Chrome extension that helps developers understand environment information by displaying labels on the screen based on the host and domain information of the URL. With this extension, it becomes easier to develop without misunderstanding the environment.

By showing labels on the display, Assert-env eliminates the difficulty of determining environment information that is not easily discernible from the display alone. This allows developers to have a clear understanding of the environment they are working in. Additionally, for important environments, overlays can be added to ensure that even if the labels are missed, the differences in the environments can still be distinguished.

With Assert-env, developers can save time and avoid potential mistakes by having a visual representation of the environment they are working with. This Chrome extension is a useful tool for anyone involved in web development.